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, a, b, c, c2, d, c1 = 0, ch = -2, c3, m;
  cin >> n >> m;
  int arr1[m + 1], arr2[m + 1];
  vector<int> v[n + 1], v2;
  int x, y;
  int x1, y1;
  for (int i = 0; i < m; i++) {
    cin >> a >> b;
    arr1[i] = a;
    arr2[i] = b;
    v[a].push_back(i);
    v[b].push_back(i);
  }
  for (int i = 1; i < n + 1; i++) {
    if (v[i].size() >= (m) / 2) v2.push_back(i);
  }
  for (int i1 = 0; i1 < v2.size(); i1++) {
    c = v2[i1];
    d = -1;
    ch = 0;
    c2 = -1;
    c3 = -1;
    for (int i = 0; i < m; i++) {
      if (arr1[i] == c || arr2[i] == c) continue;
      if (ch == 0) {
        if (c2 == -1) {
          c2 = arr1[i];
          c3 = arr2[i];
          continue;
        }
      }
      if (arr1[i] == c2) {
        if (arr2[i] == c3)
          continue;
        else
          c3 = c2;
      } else {
        if (arr1[i] == c3) {
          if (arr2[i] == c2)
            continue;
          else
            c2 = c3;
        } else if (arr2[i] == c2) {
          c3 = c2;
        } else if (arr2[i] == c3) {
          c2 = c3;
        } else {
          ch = 2;
        }
      }
    }
    if (ch == 0 || ch == 1) {
      break;
    }
  }
  if (ch == 1 || ch == 0) {
    cout << "YES";
  } else {
    cout << "NO";
  }
}
