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;
vector<pair<int, int>> pairs;
bool ok(long long x, long long y) {
  for (pair<int, int> p : pairs) {
    if (p.first != x && p.first != y && p.second != x && p.second != y) {
      return false;
    }
  }
  return true;
}
int main() {
  long long n, m, a, b;
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    cin >> a >> b;
    pairs.emplace_back(a, b);
  }
  for (long long x : {pairs[0].first, pairs[0].second}) {
    if (ok(x, -1)) {
      cout << "YES";
      return 0;
    }
    for (long long i = 1; i < m; i++) {
      if (x != pairs[i].first && x != pairs[i].second) {
        if (ok(x, pairs[i].first) || ok(x, pairs[i].second)) {
          cout << "YES";
          return 0;
        }
        break;
      }
    }
  }
  cout << "NO";
  return 0;
}
