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 f[300005][2];
bool check(int x, int y, int m) {
  for (int i = 0; i < m; i++) {
    if (x != f[i][0] && x != f[i][1] && y != f[i][0] && y != f[i][1])
      return false;
  }
  return true;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, m;
  cin >> n >> m;
  int prob[2][2] = {};
  for (int i = 0; i < m; i++) {
    cin >> f[i][0] >> f[i][1];
    if (i == 0) {
      prob[0][0] = f[0][0];
      prob[0][1] = f[0][1];
    } else if (f[i][0] != prob[0][0] && f[i][1] != prob[0][1] &&
               f[i][0] != prob[0][1] && f[i][1] != prob[0][0]) {
      prob[1][0] = f[i][0];
      prob[1][1] = f[i][1];
    }
  }
  if (prob[1][0] == 0 && prob[1][1] == 0) {
    cout << "YES";
    return 0;
  }
  if (check(prob[0][0], prob[1][0], m)) {
    cout << "YES";
  } else if (check(prob[0][0], prob[1][1], m)) {
    cout << "YES";
  } else if (check(prob[0][1], prob[1][0], m)) {
    cout << "YES";
  } else if (check(prob[0][1], prob[1][1], m)) {
    cout << "YES";
  } else
    cout << "NO";
}
