Polycarp thinks about the meaning of life very often. He does this constantly, even when typing in the editor. Every time he starts brooding he can no longer fully concentrate and repeatedly presses the keys that need to be pressed only once. For example, instead of the phrase "how are you" he can type "hhoow aaaare yyoouu". 

Polycarp decided to automate the process of correcting such errors. He decided to write a plug-in to the text editor that will remove pairs of identical consecutive letters (if there are any in the text). Of course, this is not exactly what Polycarp needs, but he's got to start from something! 

Help Polycarp and write the main plug-in module. Your program should remove from a string all pairs of identical letters, which are consecutive. If after the removal there appear new pairs, the program should remove them as well. Technically, its work should be equivalent to the following: while the string contains a pair of consecutive identical letters, the pair should be deleted. Note that deleting of the consecutive identical letters can be done in any order, as any order leads to the same result. 

Input

The input data consists of a single line to be processed. The length of the line is from 1 to 2·105 characters inclusive. The string contains only lowercase Latin letters. 

Output

Print the given string after it is processed. It is guaranteed that the result will contain at least one character.

Examples

Input

hhoowaaaareyyoouu


Output

wre

Input

reallazy


Output

rezy

Input

abacabaabacabaa


Output

a
/*
 * Hello! You are trying to hack my solution, are you? =)
 * Don't be afraid of the size, it's just a dump of useful methods like gcd, or n-th Fib number.
 * And I'm just too lazy to create a new .java for every task.
 * And if you were successful to hack my solution, please, send me this test as a message or to Abrackadabraa@gmail.com.
 * It can help me improve my skills and i'd be very grateful for that.
 * Sorry for time you spent reading this message. =)
 * Good luck, unknown rival. =)
 * */

import java.io.*;
import java.math.*;
import java.util.*;

public class Abra {
	// double d = 2.2250738585072012e-308;
	void solve() throws IOException {
        char[] a = nextString().toCharArray();
        char[] s = new char[a.length];
        int ns = 0;
        for(int i=0;i<a.length;++i) {
            s[ns++] = a[i];
            while(ns >= 2 && s[ns-1] == s[ns-2]) ns -= 2;
        }
        out.println(new String(s, 0, ns));
	}
	public static void main(String[] args) throws IOException {
		new Abra().run();
	}

	StreamTokenizer in;
	PrintWriter out;
	boolean oj;
	BufferedReader br;

	void init() throws IOException {
		oj = System.getProperty("ONLINE_JUDGE") != null;
		Reader reader = oj ? new InputStreamReader(System.in) : new FileReader("input.txt");
		Writer writer = oj ? new OutputStreamWriter(System.out) : new FileWriter("output.txt");
		br = new BufferedReader(reader);
		in = new StreamTokenizer(br);
		out = new PrintWriter(writer);
	}

	long beginTime;
	
	void run() throws IOException {
		beginTime = System.currentTimeMillis();
		long beginMem = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();
		init();
		solve();
		long endMem = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();
		long endTime = System.currentTimeMillis();
		if (!oj) {
			System.out.println("Memory used = " + (endMem - beginMem));
			System.out.println("Total memory = " + (Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()));
			System.out.println("Running time = " + (endTime - beginTime));
		}
		out.flush();
	}

	int nextInt() throws IOException {
		in.nextToken();
		return (int) in.nval;
	}

	long nextLong() throws IOException {
		in.nextToken();
		return (long) in.nval;
	}

	String nextString() throws IOException {
		in.nextToken();
		return in.sval;
	}

	double nextDouble() throws IOException {
		in.nextToken();
		return in.nval;
	}

	myLib lib = new myLib();
	
	void time() {
		System.out.print("It's ");
		System.out.println(System.currentTimeMillis() - beginTime);
	}

	static class myLib {
		long fact(long x) {
			long a = 1;
			for (long i = 2; i <= x; i++) {
				a *= i;
			}
			return a;
		}

		long digitSum(String x) {
			long a = 0;
			for (int i = 0; i < x.length(); i++) {
				a += x.charAt(i) - '0';
			}
			return a;
		}

		long digitSum(long x) {
			long a = 0;
			while (x > 0) {
				a += x % 10;
				x /= 10;
			}
			return a;
		}

		long digitMul(long x) {
			long a = 1;
			while (x > 0) {
				a *= x % 10;
				x /= 10;
			}
			return a;
		}

		int digitCubesSum(int x) {
			int a = 0;
			while (x > 0) {
				a += (x % 10) * (x % 10) * (x % 10);
				x /= 10;
			}
			return a;
		}

		double pif(double ax, double ay, double bx, double by) {
			return Math.sqrt((ax - bx) * (ax - bx) + (ay - by) * (ay - by));
		}

		double pif3D(double ax, double ay, double az, double bx, double by, double bz) {
			return Math.sqrt((ax - bx) * (ax - bx) + (ay - by) * (ay - by) + (az - bz) * (az - bz));
		}

		double pif3D(double[] a, double[] b) {
			return Math.sqrt((a[0] - b[0]) * (a[0] - b[0]) + (a[1] - b[1]) * (a[1] - b[1]) + (a[2] - b[2]) * (a[2] - b[2]));
		}

		long gcd(long a, long b) {
			if (a == 0 || b == 0) return 1;
			if (a < b) {
				long c = b;
				b = a;
				a = c;
			}
			while (a % b != 0) {
				a = a % b;
				if (a < b) {
					long c = b;
					b = a;
					a = c;
				}
			}
			return b;
		}

		int gcd(int a, int b) {
			if (a == 0 || b == 0) return 1;
			if (a < b) {
				int c = b;
				b = a;
				a = c;
			}
			while (a % b != 0) {
				a = a % b;
				if (a < b) {
					int c = b;
					b = a;
					a = c;
				}
			}
			return b;
		}

		long lcm(long a, long b) {
			return a * b / gcd(a, b);
		}

		int lcm(int a, int b) {
			return a * b / gcd(a, b);
		}

		int countOccurences(String x, String y) {
			int a = 0, i = 0;
			while (true) {
				i = y.indexOf(x);
				if (i == -1) break;
				a++;
				y = y.substring(i + 1);
			}
			return a;
		}

		int[] findPrimes(int x) {
			boolean[] forErato = new boolean[x - 1];
			List<Integer> t = new Vector<Integer>();
			int l = 0, j = 0;
			for (int i = 2; i < x; i++) {
				if (forErato[i - 2]) continue;
				t.add(i);
				l++;
				j = i * 2;
				while (j < x) {
					forErato[j - 2] = true;
					j += i;
				}
			}
			int[] primes = new int[l];
			Iterator<Integer> iterator = t.iterator();
			for (int i = 0; iterator.hasNext(); i++) {
				primes[i] = iterator.next().intValue();
			}
			return primes;
		}

		int rev(int x) {
			int a = 0;
			while (x > 0) {
				a = a * 10 + x % 10;
				x /= 10;
			}
			return a;
		}

		class myDate {
			int d, m, y;

			int[] ml = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

			public myDate(int da, int ma, int ya) {
				d = da;
				m = ma;
				y = ya;
				if ((ma > 12 || ma < 1 || da > ml[ma - 1] || da < 1) && !(d == 29 && m == 2 && y % 4 == 0)) {
					d = 1;
					m = 1;
					y = 9999999;
				}
			}

			void incYear(int x) {
				for (int i = 0; i < x; i++) {
					y++;
					if (m == 2 && d == 29) {
						m = 3;
						d = 1;
						return;
					}
					if (m == 3 && d == 1) {
						if (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)) {
							m = 2;
							d = 29;
						}
						return;
					}
				}
			}

			boolean less(myDate x) {
				if (y < x.y) return true;
				if (y > x.y) return false;
				if (m < x.m) return true;
				if (m > x.m) return false;
				if (d < x.d) return true;
				if (d > x.d) return false;
				return true;
			}

			void inc() {
				if ((d == 31) && (m == 12)) {
					y++;
					d = 1;
					m = 1;
				} else {
					if (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)) {
						ml[1] = 29;
					}
					if (d == ml[m - 1]) {
						m++;
						d = 1;
					} else
						d++;
				}
			}
		}

		int partition(int n, int l, int m) {// n - sum, l - length, m - every
											// part
			// <= m
			if (n < l) return 0;
			if (n < l + 2) return 1;
			if (l == 1) return 1;
			int c = 0;
			for (int i = Math.min(n - l + 1, m); i >= (n + l - 1) / l; i--) {
				c += partition(n - i, l - 1, i);
			}
			return c;
		}

		int rifmQuality(String a, String b) {
			if (a.length() > b.length()) {
				String c = a;
				a = b;
				b = c;
			}
			int c = 0, d = b.length() - a.length();
			for (int i = a.length() - 1; i >= 0; i--) {
				if (a.charAt(i) == b.charAt(i + d)) c++;
				else
					break;
			}
			return c;
		}

		String numSym = "0123456789ABCDEF";

		String ZFromXToYNotation(int x, int y, String z) {
			if (z.equals("0")) return "0";
			String a = "";
			// long q = 0, t = 1;
			BigInteger q = BigInteger.ZERO, t = BigInteger.ONE;
			for (int i = z.length() - 1; i >= 0; i--) {
				q = q.add(t.multiply(BigInteger.valueOf(z.charAt(i) - 48)));
				t = t.multiply(BigInteger.valueOf(x));
			}
			while (q.compareTo(BigInteger.ZERO) == 1) {
				a = numSym.charAt((int) (q.mod(BigInteger.valueOf(y)).intValue())) + a;
				q = q.divide(BigInteger.valueOf(y));
			}
			return a;
		}

		double angleFromXY(int x, int y) {
			if ((x == 0) && (y > 0)) return Math.PI / 2;
			if ((x == 0) && (y < 0)) return -Math.PI / 2;
			if ((y == 0) && (x > 0)) return 0;
			if ((y == 0) && (x < 0)) return Math.PI;
			if (x > 0) return Math.atan((double) y / x);
			else {
				if (y > 0) return Math.atan((double) y / x) + Math.PI;
				else
					return Math.atan((double) y / x) - Math.PI;
			}
		}

		static boolean isNumber(String x) {
			try {
				Integer.parseInt(x);
			} catch (NumberFormatException ex) {
				return false;
			}
			return true;
		}

		static boolean stringContainsOf(String x, String c) {
			for (int i = 0; i < x.length(); i++) {
				if (c.indexOf(x.charAt(i)) == -1) return false;
			}
			return true;
		}

		long pow(long a, long n) { // b > 0
			if (n == 0) return 1;
			long k = n, b = 1, c = a;
			while (k != 0) {
				if (k % 2 == 0) {
					k /= 2;
					c *= c;
				} else {
					k--;
					b *= c;
				}
			}
			return b;
		}

		int pow(int a, int n) { // b > 0
			if (n == 0) return 1;
			int k = n, b = 1, c = a;
			while (k != 0) {
				if (k % 2 == 0) {
					k /= 2;
					c *= c;
				} else {
					k--;
					b *= c;
				}
			}
			return b;
		}

		double pow(double a, int n) { // b > 0
			if (n == 0) return 1;
			double k = n, b = 1, c = a;
			while (k != 0) {
				if (k % 2 == 0) {
					k /= 2;
					c *= c;
				} else {
					k--;
					b *= c;
				}
			}
			return b;
		}

		double log2(double x) {
			return Math.log(x) / Math.log(2);
		}

		int lpd(int[] primes, int x) {// least prime divisor
			int i;
			for (i = 0; primes[i] <= x / 2; i++) {
				if (x % primes[i] == 0) {
					return primes[i];
				}
			}
			;
			return x;
		}

		int np(int[] primes, int x) {// number of prime number
			for (int i = 0; true; i++) {
				if (primes[i] == x) return i;
			}
		}

		int[] dijkstra(int[][] map, int n, int s) {
			int[] p = new int[n];
			boolean[] b = new boolean[n];
			Arrays.fill(p, Integer.MAX_VALUE);
			p[s] = 0;
			b[s] = true;
			for (int i = 0; i < n; i++) {
				if (i != s) p[i] = map[s][i];
			}
			while (true) {
				int m = Integer.MAX_VALUE, mi = -1;
				for (int i = 0; i < n; i++) {
					if (!b[i] && (p[i] < m)) {
						mi = i;
						m = p[i];
					}
				}
				if (mi == -1) break;
				b[mi] = true;
				for (int i = 0; i < n; i++)
					if (p[mi] + map[mi][i] < p[i]) p[i] = p[mi] + map[mi][i];
			}
			return p;
		}

		boolean isLatinChar(char x) {
			if (((x >= 'a') && (x <= 'z')) || ((x >= 'A') && (x <= 'Z'))) return true;
			else
				return false;
		}

		boolean isBigLatinChar(char x) {
			if (x >= 'A' && x <= 'Z') return true;
			else
				return false;
		}

		boolean isSmallLatinChar(char x) {
			if (x >= 'a' && x <= 'z') return true;
			else
				return false;
		}

		boolean isDigitChar(char x) {
			if (x >= '0' && x <= '9') return true;
			else
				return false;
		}

		class NotANumberException extends Exception {
			private static final long serialVersionUID = 1L;
			String mistake;

			NotANumberException() {
				mistake = "Unknown.";
			}

			NotANumberException(String message) {
				mistake = message;
			}
		}

		class Real {
			String num = "0";
			long exp = 0;
			boolean pos = true;

			long length() {
				return num.length();
			}

			void check(String x) throws NotANumberException {
				if (!stringContainsOf(x, "0123456789+-.eE")) throw new NotANumberException("Illegal character.");
				long j = 0;
				for (long i = 0; i < x.length(); i++) {
					if ((x.charAt((int) i) == '-') || (x.charAt((int) i) == '+')) {
						if (j == 0) j = 1;
						else
							if (j == 5) j = 6;
							else
								throw new NotANumberException("Unexpected sign.");
					} else
						if ("0123456789".indexOf(x.charAt((int) i)) != -1) {
							if (j == 0) j = 2;
							else
								if (j == 1) j = 2;
								else
									if (j == 2)
									;
									else
										if (j == 3) j = 4;
										else
											if (j == 4)
											;
											else
												if (j == 5) j = 6;
												else
													if (j == 6)
													;
													else
														throw new NotANumberException("Unexpected digit.");
						} else
							if (x.charAt((int) i) == '.') {
								if (j == 0) j = 3;
								else
									if (j == 1) j = 3;
									else
										if (j == 2) j = 3;
										else
											throw new NotANumberException("Unexpected dot.");
							} else
								if ((x.charAt((int) i) == 'e') || (x.charAt((int) i) == 'E')) {
									if (j == 2) j = 5;
									else
										if (j == 4) j = 5;
										else
											throw new NotANumberException("Unexpected exponent.");
								} else
									throw new NotANumberException("O_o.");
				}
				if ((j == 0) || (j == 1) || (j == 3) || (j == 5)) throw new NotANumberException("Unexpected end.");
			}

			public Real(String x) throws NotANumberException {
				check(x);
				if (x.charAt(0) == '-') pos = false;
				long j = 0;
				String e = "";
				boolean epos = true;
				for (long i = 0; i < x.length(); i++) {
					if ("0123456789".indexOf(x.charAt((int) i)) != -1) {
						if (j == 0) num += x.charAt((int) i);
						if (j == 1) {
							num += x.charAt((int) i);
							exp--;
						}
						if (j == 2) e += x.charAt((int) i);
					}
					if (x.charAt((int) i) == '.') {
						if (j == 0) j = 1;
					}
					if ((x.charAt((int) i) == 'e') || (x.charAt((int) i) == 'E')) {
						j = 2;
						if (x.charAt((int) (i + 1)) == '-') epos = false;
					}
				}
				while ((num.length() > 1) && (num.charAt(0) == '0'))
					num = num.substring(1);
				while ((num.length() > 1) && (num.charAt(num.length() - 1) == '0')) {
					num = num.substring(0, num.length() - 1);
					exp++;
				}
				if (num.equals("0")) {
					exp = 0;
					pos = true;
					return;
				}
				while ((e.length() > 1) && (e.charAt(0) == '0'))
					e = e.substring(1);
				try {
					if (e != "") if (epos) exp += Long.parseLong(e);
					else
						exp -= Long.parseLong(e);
				} catch (NumberFormatException exc) {
					if (!epos) {
						num = "0";
						exp = 0;
						pos = true;
					} else {
						throw new NotANumberException("Too long exponent");
					}
				}
			}

			public Real() {
			}

			String toString(long mantissa) {
				String a = "", b = "";
				if (exp >= 0) {
					a = num;
					if (!pos) a = '-' + a;
					for (long i = 0; i < exp; i++)
						a += '0';
					for (long i = 0; i < mantissa; i++)
						b += '0';
					if (mantissa == 0) return a;
					else
						return a + "." + b;
				} else {
					if (exp + length() <= 0) {
						a = "0";
						if (mantissa == 0) {
							return a;
						}
						if (mantissa < -(exp + length() - 1)) {
							for (long i = 0; i < mantissa; i++)
								b += '0';
							return a + "." + b;
						} else {
							if (!pos) a = '-' + a;
							for (long i = 0; i < mantissa; i++)
								if (i < -(exp + length())) b += '0';
								else
									if (i + exp >= 0) b += '0';
									else
										b += num.charAt((int) (i + exp + length()));
							return a + "." + b;
						}
					} else {
						if (!pos) a = "-";
						for (long i = 0; i < exp + length(); i++)
							a += num.charAt((int) i);
						if (mantissa == 0) return a;
						for (long i = exp + length(); i < exp + length() + mantissa; i++)
							if (i < length()) b += num.charAt((int) i);
							else
								b += '0';
						return a + "." + b;
					}
				}
			}
		}

		boolean containsRepeats(int... num) {
			Set<Integer> s = new TreeSet<Integer>();
			for (int d : num)
				if (!s.contains(d)) s.add(d);
				else
					return true;
			return false;
		}

		int[] rotateDice(int[] a, int n) {
			int[] c = new int[6];
			if (n == 0) {
				c[0] = a[1];
				c[1] = a[5];
				c[2] = a[2];
				c[3] = a[0];
				c[4] = a[4];
				c[5] = a[3];
			}
			if (n == 1) {
				c[0] = a[2];
				c[1] = a[1];
				c[2] = a[5];
				c[3] = a[3];
				c[4] = a[0];
				c[5] = a[4];
			}
			if (n == 2) {
				c[0] = a[3];
				c[1] = a[0];
				c[2] = a[2];
				c[3] = a[5];
				c[4] = a[4];
				c[5] = a[1];
			}
			if (n == 3) {
				c[0] = a[4];
				c[1] = a[1];
				c[2] = a[0];
				c[3] = a[3];
				c[4] = a[5];
				c[5] = a[2];
			}
			if (n == 4) {
				c[0] = a[0];
				c[1] = a[2];
				c[2] = a[3];
				c[3] = a[4];
				c[4] = a[1];
				c[5] = a[5];
			}
			if (n == 5) {
				c[0] = a[0];
				c[1] = a[4];
				c[2] = a[1];
				c[3] = a[2];
				c[4] = a[3];
				c[5] = a[5];
			}
			return c;
		}

		int min(int... a) {
			int c = Integer.MAX_VALUE;
			for (int d : a)
				if (d < c) c = d;
			return c;
		}

		int max(int... a) {
			int c = Integer.MIN_VALUE;
			for (int d : a)
				if (d > c) c = d;
			return c;
		}

		int pos(int x) {
			if (x > 0) return x;
			else
				return 0;
		}

		long pos(long x) {
			if (x > 0) return x;
			else
				return 0;
		}

		double maxD(double... a) {
			double c = Double.MIN_VALUE;
			for (double d : a)
				if (d > c) c = d;
			return c;
		}

		double minD(double... a) {
			double c = Double.MAX_VALUE;
			for (double d : a)
				if (d < c) c = d;
			return c;
		}

		int[] normalizeDice(int[] a) {
			int[] c = a.clone();
			if (c[0] != 0) if (c[1] == 0) c = rotateDice(c, 0);
			else
				if (c[2] == 0) c = rotateDice(c, 1);
				else
					if (c[3] == 0) c = rotateDice(c, 2);
					else
						if (c[4] == 0) c = rotateDice(c, 3);
						else
							if (c[5] == 0) c = rotateDice(rotateDice(c, 0), 0);
			while (c[1] != min(c[1], c[2], c[3], c[4]))
				c = rotateDice(c, 4);
			return c;
		}

		boolean sameDice(int[] a, int[] b) {
			for (int i = 0; i < 6; i++)
				if (a[i] != b[i]) return false;
			return true;
		}

		final double goldenRatio = (1 + Math.sqrt(5)) / 2;
		final double aGoldenRatio = (1 - Math.sqrt(5)) / 2;

		long Fib(int n) {
			if (n < 0) if (n % 2 == 0) return -Math.round((pow(goldenRatio, -n) - pow(aGoldenRatio, -n)) / Math.sqrt(5));
			else
				return -Math.round((pow(goldenRatio, -n) - pow(aGoldenRatio, -n)) / Math.sqrt(5));
			return Math.round((pow(goldenRatio, n) - pow(aGoldenRatio, n)) / Math.sqrt(5));
		}

		class japaneeseComparator implements Comparator<String> {
			@Override
			public int compare(String a, String b) {
				int ai = 0, bi = 0;
				boolean m = false, ns = false;
				if (a.charAt(ai) <= '9' && a.charAt(ai) >= '0') {
					if (b.charAt(bi) <= '9' && b.charAt(bi) >= '0') m = true;
					else
						return -1;
				}
				if (b.charAt(bi) <= '9' && b.charAt(bi) >= '0') {
					if (a.charAt(ai) <= '9' && a.charAt(ai) >= '0') m = true;
					else
						return 1;
				}
				a += "!";
				b += "!";
				int na = 0, nb = 0;
				while (true) {
					if (a.charAt(ai) == '!') {
						if (b.charAt(bi) == '!') break;
						return -1;
					}
					if (b.charAt(bi) == '!') {
						return 1;
					}
					if (m) {
						int ab = -1, bb = -1;
						while (a.charAt(ai) <= '9' && a.charAt(ai) >= '0') {
							if (ab == -1) ab = ai;
							ai++;
						}
						while (b.charAt(bi) <= '9' && b.charAt(bi) >= '0') {
							if (bb == -1) bb = bi;
							bi++;
						}
						m = !m;
						if (ab == -1) {
							if (bb == -1) continue;
							else
								return 1;
						}
						if (bb == -1) return -1;
						while (a.charAt(ab) == '0' && ab + 1 != ai) {
							ab++;
							if (!ns) na++;
						}
						while (b.charAt(bb) == '0' && bb + 1 != bi) {
							bb++;
							if (!ns) nb++;
						}
						if (na != nb) ns = true;
						if (ai - ab < bi - bb) return -1;
						if (ai - ab > bi - bb) return 1;
						for (int i = 0; i < ai - ab; i++) {
							if (a.charAt(ab + i) < b.charAt(bb + i)) return -1;
							if (a.charAt(ab + i) > b.charAt(bb + i)) return 1;
						}
					} else {
						m = !m;
						while (true) {
							if (a.charAt(ai) <= 'z' && a.charAt(ai) >= 'a' && b.charAt(bi) <= 'z' && b.charAt(bi) >= 'a') {
								if (a.charAt(ai) < b.charAt(bi)) return -1;
								if (a.charAt(ai) > b.charAt(bi)) return 1;
								ai++;
								bi++;
							} else
								if (a.charAt(ai) <= 'z' && a.charAt(ai) >= 'a') return 1;
								else
									if (b.charAt(bi) <= 'z' && b.charAt(bi) >= 'a') return -1;
									else
										break;
						}
					}
				}
				if (na < nb) return 1;
				if (na > nb) return -1;
				return 0;
			}
		}

		Random random = new Random();
	}

	void readIntArray(int[] a) throws IOException {
		for (int i = 0; i < a.length; i++)
			a[i] = nextInt();
	}

	String readChars(int l) throws IOException {
		String r = "";
		for (int i = 0; i < l; i++)
			r += (char) br.read();
		return r;
	}

	class myFraction {
		long num = 0, den = 1;

		void reduce() {
			long d = lib.gcd(num, den);
			num /= d;
			den /= d;
		}

		myFraction(long ch, long zn) {
			num = ch;
			den = zn;
			reduce();
		}

		myFraction add(myFraction t) {
			long nd = lib.lcm(den, t.den);
			myFraction r = new myFraction(nd / den * num + nd / t.den * t.num, nd);
			r.reduce();
			return r;
		}

		public String toString() {
			return num + "/" + den;
		}
		
		int lev(String s1, String s2) {
			int[][] distance = new int[s1.length() + 1][s2.length() + 1];
			for (int i = 0; i <= s1.length(); i++)
	            distance[i][0] = i;
			for (int j = 0; j <= s2.length(); j++)
	            distance[0][j] = j;
			for (int i = 1; i <= s1.length(); i++)
	            for (int j = 1; j <= s2.length(); j++)
	                    distance[i][j] = Math.min(Math.min(distance[i - 1][j] + 1, distance[i][j - 1] + 1), distance[i - 1][j - 1] + ((s1.charAt(i - 1) == s2.charAt(j - 1)) ? 0 : 1));
			return distance[s1.length()][s2.length()];
		}
	}

	class myPoint {
		myPoint(int a, int b) {
			x = a;
			y = b;
		}

		int x, y;

		boolean equals(myPoint a) {
			if (x == a.x && y == a.y) return true;
			else
				return false;
		}

		public String toString() {
			return x + ":" + y;
		}
	}
}