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 Data {
  int a, b;
} data[(int)3e5 + 5];
bool vis[(int)3e5 + 5];
bool nvis[(int)3e5 + 5];
int main() {
  int n, m;
  while (cin >> n >> m) {
    memset(data, 0, sizeof(data));
    memset(vis, 0, sizeof(vis));
    memset(nvis, 0, sizeof(nvis));
    for (int i = 0; i < m; i++) {
      cin >> data[i].a >> data[i].b;
    }
    for (int cnt = 0; cnt < 2; cnt++) {
      memset(vis, 0, sizeof(vis));
      int num = cnt > 0 ? data[0].a : data[0].b;
      int postion = -1;
      for (int i = 0; i < m; i++) {
        if (data[i].a == num || data[i].b == num) {
          vis[i] = 1;
          continue;
        }
        postion = i;
      }
      if (postion == -1) {
        cout << "YES" << endl;
        break;
      }
      memcpy(nvis, vis, sizeof(vis));
      num = data[postion].a;
      bool flagA = 1;
      for (int i = 0; i < m; i++) {
        if (vis[i]) continue;
        if (data[i].a == num || data[i].b == num)
          vis[i] = 1;
        else {
          flagA = 0;
          break;
        }
      }
      memcpy(vis, nvis, sizeof(vis));
      num = data[postion].b;
      bool flagB = 1;
      for (int i = 0; i < m; i++) {
        if (vis[i]) continue;
        if (data[i].a == num || data[i].b == num)
          vis[i] = 1;
        else {
          flagB = 0;
          break;
        }
      }
      if (flagA || flagB) {
        cout << "YES" << endl;
        break;
      } else if (cnt == 1 && !flagA && !flagB) {
        cout << "NO" << endl;
      }
    }
  }
}
