Toad Ivan has m pairs of integers, each integer is between 1 and n, inclusive. The pairs are (a_1, b_1), (a_2, b_2), …, (a_m, b_m). 

He asks you to check if there exist two integers x and y (1 ≤ x < y ≤ n) such that in each given pair at least one integer is equal to x or y.

Input

The first line contains two space-separated integers n and m (2 ≤ n ≤ 300 000, 1 ≤ m ≤ 300 000) — the upper bound on the values of integers in the pairs, and the number of given pairs.

The next m lines contain two integers each, the i-th of them contains two space-separated integers a_i and b_i (1 ≤ a_i, b_i ≤ n, a_i ≠ b_i) — the integers in the i-th pair.

Output

Output "YES" if there exist two integers x and y (1 ≤ x < y ≤ n) such that in each given pair at least one integer is equal to x or y. Otherwise, print "NO". You can print each letter in any case (upper or lower).

Examples

Input


4 6
1 2
1 3
1 4
2 3
2 4
3 4


Output


NO


Input


5 4
1 2
2 3
3 4
4 5


Output


YES


Input


300000 5
1 2
1 2
1 2
1 2
1 2


Output


YES

Note

In the first example, you can't choose any x, y because for each such pair you can find a given pair where both numbers are different from chosen integers.

In the second example, you can choose x=2 and y=4.

In the third example, you can choose x=1 and y=2.
import java.util.*; 
import java.io.*;

public class Main {
	public static long maximum(long a[]) {
		long ans = -1; 
		for(long i : a) {
			ans = Math.max(i, ans); 
		}
		return ans ; 
	}
	public static void solve(InputReader in) {
		int n = in.readInt(); 
		int m = in.readInt();  
		pair p[] = new pair[m]; 
		for(int i = 0; i<m; i++) {
			int a = in.readInt(); 
			int b = in.readInt(); 
			p[i] = new pair(--a , --b);
		}
		long values[] = {p[0].first , p[0].second}; 
		for(long x : values) {
			long val[] = new long[n]; 
			long all = 0; 
			for(pair i : p) {
				if(i.first != x && i.second != x) {
					val[(int)i.first]++; 
					val[(int)i.second]++; 
					all++; 
				}
			}
			if(maximum(val) == all) {
				System.out.println("YES"); 
				return; 
			}
		}
		System.out.println("NO"); 
	}
	public static void main(String[] args) {
		InputReader in = new InputReader(System.in); 
		int t = 1; 
		while(t-- > 0) {
			solve(in); 
		}
	}
}

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 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 readInt() {
		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 String readString() {
		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 long readLong() {
		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 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 readString();
	}
    
     public interface SpaceCharFilter {
		public boolean isSpaceChar(int ch);
	}
}
class pair implements Comparable<pair> {
	long first; 
	long second; 
	pair(long a, long b ) {
		this.first = a;
		this.second = b;
	}
    public long getFirst() {
    	return first; 
    }
    public long getSecond() {
    	return second; 
    }
	public String toString() {
		return first + " " + second;
	}

	public boolean equals(Object o) {
		return o instanceof pair && ((pair) o).first == first && ((pair) o).second == second;
	}

	public int compareTo(pair a) {
		return Long.compare(first, a.first); 
	}
}