One day Misha and Andrew were playing a very simple game. First, each player chooses an integer in the range from 1 to n. Let's assume that Misha chose number m, and Andrew chose number a.

Then, by using a random generator they choose a random integer c in the range between 1 and n (any integer from 1 to n is chosen with the same probability), after which the winner is the player, whose number was closer to c. The boys agreed that if m and a are located on the same distance from c, Misha wins.

Andrew wants to win very much, so he asks you to help him. You know the number selected by Misha, and number n. You need to determine which value of a Andrew must choose, so that the probability of his victory is the highest possible.

More formally, you need to find such integer a (1 ≤ a ≤ n), that the probability that <image> is maximal, where c is the equiprobably chosen integer from 1 to n (inclusive).

Input

The first line contains two integers n and m (1 ≤ m ≤ n ≤ 109) — the range of numbers in the game, and the number selected by Misha respectively.

Output

Print a single number — such value a, that probability that Andrew wins is the highest. If there are multiple such values, print the minimum of them.

Examples

Input

3 1


Output

2

Input

4 3


Output

2

Note

In the first sample test: Andrew wins if c is equal to 2 or 3. The probability that Andrew wins is 2 / 3. If Andrew chooses a = 3, the probability of winning will be 1 / 3. If a = 1, the probability of winning is 0.

In the second sample test: Andrew wins if c is equal to 1 and 2. The probability that Andrew wins is 1 / 2. For other choices of a the probability of winning is less.
    import java.util.*;
    import java.io.*;
     
    public class Main {

	static InputReader scn = new InputReader(System.in);
	static PrintWriter out = new PrintWriter(System.out);
	
	public static void main(String[] HastaLaVistaLa) {
		// Running Number Of TestCases (t)
		int t = 1;	
		while(t-- > 0)
			solve();
		out.close();
	}

	public static void dummy(){
		int n = scn.nextInt();
		out.println(n);
	}

	static long MOD = 1000000007L;
	public static void solve() {
		// Main Solution (AC)
		int n = scn.nextInt();
		int m = scn.nextInt();
		if(n == 1 && m == 1) out.println(1);
		else if(m == 1) out.println(2);
		else {
			if(m > n / 2) out.println(m - 1);
			else out.println(m + 1);
		}
	}

	public static StringBuilder ZeroGen(StringBuilder a, int n) {
		StringBuilder ans = new StringBuilder();
		ans.append(a);
		while(ans.length() < n) ans.append("0");
		return ans;
	}

	public static long mod(long a) {
		if(a < 0) return a + MOD;
		if(a > MOD) return a - MOD;
		return a % MOD;
	}

	public static long binpow(long n, long m, long mod) {
	        long res = 1;
	        while (m > 0) {
	            if (m % 2 == 1) {
	                res *= n;
	                res %= mod;
	                m--;
	            }
	            n *= n;
	            n %= mod;
	            m /= 2;
	        }
	        return res;
    	}

	public static HashMap<Integer, Integer> CountFrequencies(int[] arr) {
		HashMap<Integer, Integer> map = new HashMap<>();
		for (int i : arr) {
			if (map.containsKey(i)) map.put(i, map.get(i) + 1);
			else map.put(i, 1);
		}
		return map;
	}

	public static long gcd(long a, long b) {
		if (a == 0)
			return b;
		return gcd(b % a, a);
	}

	public static long sum(int[] arr) {
	    	long sum = 0;
	    	for(int i : arr) sum += i;
	    	return sum;
	}

	// Number of Divisor for Range [l, r]
	public static int[] NumberOFDivisors(int l, int r) {
		int[] arr = new int[l - r + 1];
		for(int i = l; i <= r; i++) {
			for(int j = i; j <= r; j += i)
				arr[j]++;
		}
		return arr;
	}

	public static int LowerBound(int a[], int x) { // x is the target value or key

		  int l = -1,r = a.length;
		  while(l + 1 < r) {

		    int m = (l + r) >>> 1;
		    if(a[m] >= x) r = m;
		    else l = m;

		  }
		  return r;
	}

	static boolean[] prime;
	public static void sieveOfEratosthenes(int n) {
        	prime = new boolean[n+1];
	        for(int i=0;i<n;i++)
	            prime[i] = true;
	          
	        for(int p = 2; p*p <=n; p++) {

	            if(prime[p] == true) {

	                for(int i = p*p; i <= n; i += p)
	                    prime[i] = false;
	            }
	        }
    	}

	public static int UpperBound(long a[], long x) {// x is the key or target value

		    int l = -1,r = a.length;

		    while(l + 1 < r) {

		       int m = (l + r) >>> 1;
		       if(a[m] <= x) l = m;
		       else r = m;

		    }
		    return l + 1;
	}

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

	public static void sort(int[] arr) {
		Random rand = new Random();
		int n = arr.length;
		for(int i = 0; i<n; i++) {
			swap(arr, i, rand.nextInt(n));
		}
		Arrays.sort(arr);
	}

	public static void swap(int[] arr, int i, int j) {
		if(i!=j) {
			arr[i] ^= arr[j];
			arr[j] ^= arr[i];
			arr[i] ^= arr[j];
		}
	}
     
	public static void sortbyColumn(int[][] arr, int col) {
		Arrays.sort(arr, new Comparator<int[]>() {
			public int compare(final int[] entry1, final int[] entry2) {
				if (entry1[col] > entry2[col])
					return 1;
				else
					return -1;
			}
		});
	}

	public static void ArraySort2D(double[][] arr, int xy) {
		// xy == 0, for sorting wrt X-Axis
		// xy == 1, for sorting wrt Y-Axis
		Arrays.sort(arr, Comparator.comparingDouble(o -> o[xy]));
	}
	
	public static int binarySearch(int arr[], int l, int r, int x) {
		if (r >= l) {
			int mid = l + (r - l) / 2;
			if (arr[mid] == x)
				return mid;
			if (arr[mid] > x)
				return binarySearch(arr, l, mid - 1, x);
			return binarySearch(arr, mid + 1, r, x);
		}
		return -1;
	}
     
	static class InputReader {
		private InputStream stream;
		private byte[] buf = new byte[1024];
		private int curChar;
		private int numChars;
		private SpaceCharFilter filter;
     
		public InputReader(InputStream stream) {
			this.stream = stream;
		}
     
		public int[] readIntArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++) {
				a[i] = scn.nextInt();
			}
			return a;
		}
     			
     		public long[] readLongArray(int n) {
			long[] a = new long[n];
			for (int i = 0; i < n; i++) {
				a[i] = scn.nextLong();
			}
			return a;
		}

		public int read() {
			if (numChars == -1)
				throw new InputMismatchException();
			if (curChar >= numChars) {
				curChar = 0;
				try {
					numChars = stream.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (numChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}
     
		public int nextInt() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
     
		public long nextLong() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
     
		public String nextLine() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}
     
		public boolean isSpaceChar(int c) {
			if (filter != null)
				return filter.isSpaceChar(c);
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
     
		public String next() {
			return nextLine();
		}
     
		public interface SpaceCharFilter {
			public boolean isSpaceChar(int ch);
		}
	}
}