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.
#include <bits/stdc++.h>
using namespace std;
struct var {
  int a, b;
  bool c;
};
int main() {
  int n, m;
  cin >> n >> m;
  struct var s[m];
  for (int i = 0; i < m; i++) {
    cin >> s[i].a >> s[i].b;
    s[i].c = 0;
  }
  bool f = 0;
  int x = s[0].a, y = s[0].b, p, q;
  for (int i = 0; i < m; i++) {
    if (s[i].a != x && s[i].b != x && s[i].a != y && s[i].b != y) {
      f = 1;
      p = s[i].a;
      q = s[i].b;
      break;
    }
  }
  if (f == 0) {
    cout << "YES";
    return 0;
  }
  int y1 = p;
  f = 0;
  for (int i = 0; i < m; i++) s[i].c = 0;
  for (int i = 0; i < m; i++) {
    if (s[i].a == x || s[i].b == x || s[i].a == y1 || s[i].b == y1) s[i].c = 1;
  }
  for (int i = 0; i < m; i++) {
    if (s[i].c == 0) {
      f = 1;
      break;
    }
  }
  if (f == 0) {
    cout << "YES";
    return 0;
  }
  if (f == 1) {
    f = 0;
    for (int i = 0; i < m; i++) s[i].c = 0;
    int y2 = q;
    for (int i = 0; i < m; i++) {
      if (s[i].a == x || s[i].b == x || s[i].a == y2 || s[i].b == y2)
        s[i].c = 1;
    }
    for (int i = 0; i < m; i++) {
      if (s[i].c == 0) {
        f = 1;
        break;
      }
    }
    if (f == 0) {
      cout << "YES";
      return 0;
    }
    if (f == 1) {
      f = 0;
      for (int i = 0; i < m; i++) s[i].c = 0;
      int x1 = y, y3 = p;
      for (int i = 0; i < m; i++) {
        if (s[i].a == x1 || s[i].b == x1 || s[i].a == y3 || s[i].b == y3)
          s[i].c = 1;
      }
      for (int i = 0; i < m; i++) {
        if (s[i].c == 0) {
          f = 1;
          break;
        }
      }
      if (f == 0) {
        cout << "YES";
        return 0;
      }
      if (f == 1) {
        f = 0;
        int y4 = q;
        for (int i = 0; i < m; i++) s[i].c = 0;
        for (int i = 0; i < m; i++) {
          if (s[i].a == x1 || s[i].b == x1 || s[i].a == y4 || s[i].b == y4)
            s[i].c = 1;
        }
        for (int i = 0; i < m; i++) {
          if (s[i].c == 0) {
            f = 1;
            break;
          }
        }
        if (f == 0) {
          cout << "YES";
          return 0;
        } else {
          cout << "NO";
          return 0;
        }
      }
    }
  }
}
