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;
int main() {
  int n, m;
  cin >> n >> m;
  int a[m], b[m];
  int arr[4] = {0};
  for (int i = 0; i < m; i++) {
    cin >> a[i] >> b[i];
  }
  arr[0] = a[0];
  arr[1] = b[0];
  int cnt = 1;
  int flag = 1;
  for (int i = 1; i < m; i++) {
    if (a[i] == arr[0] || b[i] == arr[0])
      cnt++;
    else
      break;
  }
  arr[2] = a[cnt];
  arr[3] = b[cnt];
  for (int i = cnt + 1; i < m; i++) {
    if (a[i] == arr[0] || b[i] == arr[0] || a[i] == arr[2] || arr[2] == b[i])
      ;
    else {
      flag = 0;
      break;
    }
  }
  if (!flag) {
    flag = 1;
    for (int i = cnt + 1; i < m; i++) {
      if (a[i] == arr[0] || b[i] == arr[0] || a[i] == arr[3] || arr[3] == b[i])
        ;
      else {
        flag = 0;
        break;
      }
    }
    if (!flag) {
      cnt = 1;
      flag = 1;
      for (int i = 1; i < m; i++) {
        if (a[i] == arr[1] || b[i] == arr[1])
          cnt++;
        else
          break;
      }
      arr[2] = a[cnt];
      arr[3] = b[cnt];
      for (int i = cnt + 1; i < m; i++) {
        if (a[i] == arr[1] || b[i] == arr[1] || a[i] == arr[2] ||
            arr[2] == b[i])
          ;
        else {
          flag = 0;
          break;
        }
      }
      if (!flag) {
        flag = 1;
        for (int i = cnt + 1; i < m; i++) {
          if (a[i] == arr[1] || b[i] == arr[1] || a[i] == arr[3] ||
              arr[3] == b[i])
            ;
          else {
            flag = 0;
            break;
          }
        }
      }
    }
  }
  if (flag)
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
