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.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;

public class Pairs1 {
    static class P {
        int i;
        int j;

        public P(int i, int j) {
            this.i = i;
            this.j = j;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (!(o instanceof P)) return false;

            P p = (P) o;

            if (i != p.i) return false;
            return j == p.j;

        }

        @Override
        public int hashCode() {
            int result = i;
            result = 31 * result + j;
            return result;
        }
    }

    public static void main(String[] args) {
        HashMap<Integer, Integer> countMap = new HashMap<>();
        HashMap<P, Integer> pairCount = new HashMap<>();

        Scanner in = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        int n = in.nextInt();
        int m = in.nextInt();
        for (int i = 0; i < m; i++) {
            int a = in.nextInt();
            int b = in.nextInt();
            P p;
            if (a < b) {
                p = new P(a, b);
            } else {
                p = new P(b, a);
            }
            Integer countP = pairCount.get(p);
            if (countP == null) {
                countP = 1;
            } else {
                countP++;
            }
            pairCount.put(p, countP);

            Integer countA = countMap.get(a);
            if (countA == null) {
                countA = 1;
            } else {
                countA++;
            }
            countMap.put(a, countA);

            Integer countB = countMap.get(b);
            if (countB == null) {
                countB = 1;
            } else {
                countB++;
            }
            countMap.put(b, countB);
        }
        
        ArrayList<Map.Entry<Integer, Integer>> entryArrayList = new ArrayList<>(countMap.entrySet());

        entryArrayList.sort((o1, o2) -> Integer.compare(o2.getValue(), o1.getValue()));
        for (int i = 0; i < entryArrayList.size(); i++) {
            Map.Entry<Integer, Integer> iEntry = entryArrayList.get(i);
            if (iEntry.getValue() < m / 2) {
                break;
            }
            for (int j = i + 1; j < entryArrayList.size(); j++) {
                Map.Entry<Integer, Integer> jEntry = entryArrayList.get(j);
                int xi = iEntry.getKey();
                int xj = jEntry.getKey();
                P p = xi < xj ? new P(xi, xj) : new P(xj, xi);
                Integer countP = pairCount.get(p);
                if (countP == null) {
                    if (iEntry.getValue() + jEntry.getValue() >= m) {
                        System.out.println("YES");
                        return;
                    }
                } else {
                    if (iEntry.getValue() + jEntry.getValue() >= m + countP) {
                        System.out.println("YES");
                        return;
                    }
                }
            }
        }
        System.out.println("NO");
    }
}
