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.lang.*;
import java.io.*;
import java.math.*;

public class Q1 {

	static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
	
	static class FastScanner {
	    private InputStream stream;
	    private byte[] buf = new byte[1024];
	    private int curChar;
	    private int numChars;
	    private SpaceCharFilter filter;
	 
	    public FastScanner(InputStream stream) {
	        this.stream = stream;
	    }
	 
	    public static boolean isWhitespace(int c) {
	        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	    }
	 
	    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 nextToken() {
	        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 isWhitespace(c);
	    }
	 
	    public interface SpaceCharFilter {
	        public boolean isSpaceChar(int ch);
	    }
	}
	
	static class Pair implements Comparable<Pair> {
		int u, v;
		
		public Pair(int u, int v) {
			this.u = u;
			this.v = v;
		}
		
		public int compareTo(Pair o) {
			return Integer.compare(u, o.u) != 0 ? Integer.compare(u, o.u) : Integer.compare(v, o.v);
		}
	}
	
	static int[] arr = new int[300001], brr = new int[300001];
	static int n, m;
	
	public static void main(String[] args) throws Exception {
		FastScanner fs = new FastScanner(System.in);
		n = fs.nextInt();
		m = fs.nextInt();
		
		for(int i=1; i<=m; i++) {
			arr[i] = fs.nextInt();
			brr[i] = fs.nextInt();
		}
		
		if(func(arr[1]) || func(brr[1]))
			pw.println("YES");
		else
			pw.println("NO");
		pw.flush();
		pw.close();
	}
	
	static boolean func(int x) {
		int[] count = new int[300001];
		int cnt = 0;
		
		for(int i=1; i<=m; i++) {
			if(arr[i] !=x && brr[i] != x) {
				count[arr[i]]++;
				count[brr[i]]++;
				cnt++;
			}
		}
		
		Arrays.sort(count , 1, n+1);
		
		if(count[n] == cnt)
			return true;
		else
			return false;
		
	}

}