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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Set;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.Objects;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Liavontsi Brechka
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        BPari solver = new BPari();
        solver.solve(1, in, out);
        out.close();
    }

    static class BPari {
        InputReader in;

        public void solve(int testNumber, InputReader in, PrintWriter out) {
            this.in = in;

            int n = ni();
            int m = ni();
            BPari.Pair[] pairs = new BPari.Pair[m];
            for (int i = 0; i < m; i++) {
                pairs[i] = new BPari.Pair(ni(), ni());
            }

            BPari.Pair first = null;
            BPari.Pair second;
            Set<BPari.Pair> toCheck = null;
            for (int i = 0; i < m; i++) {
                if (first == null) first = pairs[i];
                else {
                    second = pairs[i];

                    if (second.a != first.a && second.a != first.b && second.b != first.a && second.b != first.b) {
                        toCheck = new HashSet<>();
                        toCheck.add(new BPari.Pair(first.a, second.a));
                        toCheck.add(new BPari.Pair(first.a, second.b));
                        toCheck.add(new BPari.Pair(first.b, second.a));
                        toCheck.add(new BPari.Pair(first.b, second.b));

                        break;
                    }
                }
            }

            if (toCheck != null) {
                for (BPari.Pair pair1 : toCheck) {
                    boolean isOk = true;
                    for (BPari.Pair pair2 : pairs) {
                        if (pair1.a != pair2.a && pair1.a != pair2.b && pair1.b != pair2.a && pair1.b != pair2.b) {
                            isOk = false;
                            break;
                        }
                    }
                    if (isOk) {
                        out.println("YES");
                        return;
                    }
                }
            } else {
                out.println("YES");
                return;
            }

            out.println("NO");
        }

        private int ni() {
            return in.nextInt();
        }

        static class Pair {
            int a;
            int b;

            public Pair(int a, int b) {
                this.a = a;
                this.b = b;
            }

            public boolean equals(Object o) {
                if (this == o) return true;
                if (o == null || getClass() != o.getClass()) return false;
                BPari.Pair pair = (BPari.Pair) o;
                return a == pair.a &&
                        b == pair.b;
            }

            public int hashCode() {
                return Objects.hash(a, b);
            }

        }

    }

    static class InputReader {
        private final BufferedReader reader;
        private StringTokenizer tokenizer;

        public InputReader(InputStream in) {
            reader = new BufferedReader(new InputStreamReader(in));
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                tokenizer = new StringTokenizer(readLine());
            }
            return tokenizer.nextToken();
        }

        public String readLine() {
            String line;
            try {
                line = reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
            return line;
        }

    }
}

