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

import static java.lang.Math.*;

public class input2 {
    //    public static void merge(int arr[], int l, int m, int r) {
    //        // Find sizes of two subarrays to be merged
    //        int n1 = m - l + 1;
    //        int n2 = r - m;
    //
    //        /* Create temp arrays */
    //        int L[] = new int[n1];
    //        int R[] = new int[n2];
    //
    //        /*Copy data to temp arrays*/
    //        for (int i = 0; i < n1; ++i)
    //            L[i] = arr[l + i];
    //        for (int j = 0; j < n2; ++j)
    //            R[j] = arr[m + 1 + j];
    //
    //
    //        /* Merge the temp arrays */
    //
    //        // Initial indexes of first and second subarrays
    //        int i = 0, j = 0;
    //
    //        // Initial index of merged subarry array
    //        int k = l;
    //        while (i < n1 && j < n2) {
    //            if (L[i] <= R[j]) {
    //                arr[k] = L[i];
    //                i++;
    //            } else {
    //                arr[k] = R[j];
    //                j++;
    //            }
    //            k++;
    //        }
    //
    //        /* Copy remaining elements of L[] if any */
    //        while (i < n1) {
    //            arr[k] = L[i];
    //            i++;
    //            k++;
    //        }
    //
    //        /* Copy remaining elements of R[] if any */
    //        while (j < n2) {
    //            arr[k] = R[j];
    //            j++;
    //            k++;
    //        }
    //    }
    //
    //    // Main function that sorts arr[l..r] using
    //    // merge()
    //    public static void sort(int arr[], int l, int r) {
    //        if (l < r) {
    //            // Find the middle point
    //            int m = (l + r) / 2;
    //
    //            // Sort first and second halves
    //            sort(arr, l, m);
    //            sort(arr, m + 1, r);
    //
    //            // Merge the sorted halves
    //            merge(arr, l, m, r);
    //        }
    //    }
    //
    //    public static long gcd(long n, long m) {
    //        if (n % m == 0) {
    //            return m;
    //        }
    //        return gcd(m, n % m);
    //    }
    //
    //    static class Pair {
    //        public char x1;
    //        public int x2;
    //
    //        Pair(char x, int y) {
    //            this.x1 = x;
    //            this.x2 = y;
    //        }
    //    }
    public static int l[] = new int[300009];
    public static int r[] = new int[300009];
    public static int cnt[] = new int[300009];
    public static int n;
    public static int m;

    public static boolean ans(int x) {
        int cntx = 0;
        Arrays.fill(cnt,0);
        for (int i = 0; i < m; ++i) {
            if (x == l[i] || x == r[i])
                ++cntx;
            else {
                cnt[l[i]]++;
                cnt[r[i]]++;
            }
        }
        for (int i = 0; i <= n; ++i) {
            if ((cntx + cnt[i]) == m) {
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        n = Integer.parseInt(st.nextToken());
        m = Integer.parseInt(st.nextToken());
        for (int i = 0; i < m; i++) {
            st = new StringTokenizer(br.readLine());
            l[i] = Integer.parseInt(st.nextToken());
            r[i] = Integer.parseInt(st.nextToken());
        }
        if (ans(l[0]) || ans(r[0])) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
}