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;
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long TESTS = 1;
  while (TESTS--) {
    long long n, m;
    cin >> n >> m;
    vector<pair<long long, long long> > v(m);
    for (long long i = 0; i < m; i++) {
      cin >> v[i].first >> v[i].second;
    }
    vector<pair<long long, long long> > va;
    long long a = v[0].first, b = v[0].second;
    for (long long i = 1; i < m; i++) {
      if (v[i].first != a && v[i].second != a)
        va.push_back({v[i].first, v[i].second});
    }
    if ((long long)va.size() == 0) {
      cout << "YES";
      return 0;
    }
    long long c = va[0].first;
    long long flag = 1;
    for (long long i = 1; i < (long long)va.size(); i++) {
      if (va[i].first != c && va[i].second != c) {
        flag = 0;
        break;
      }
    }
    if (flag == 1) {
      cout << "YES";
      return 0;
    }
    long long d = va[0].second;
    flag = 1;
    for (long long i = 1; i < (long long)va.size(); i++) {
      if (va[i].first != d && va[i].second != d) {
        flag = 0;
        break;
      }
    }
    if (flag == 1) {
      cout << "YES";
      return 0;
    }
    va.clear();
    for (long long i = 1; i < m; i++) {
      if (v[i].first != b && v[i].second != b)
        va.push_back({v[i].first, v[i].second});
    }
    if ((long long)va.size() == 0) {
      cout << "YES";
      return 0;
    }
    c = va[0].first;
    flag = 1;
    for (long long i = 1; i < (long long)va.size(); i++) {
      if (va[i].first != c && v[i].second != c) {
        flag = 0;
        break;
      }
    }
    if (flag == 1) {
      cout << "YES";
      return 0;
    }
    d = va[0].second;
    flag = 1;
    for (long long i = 1; i < (long long)va.size(); i++) {
      if (va[i].first != d && va[i].second != d) {
        flag = 0;
        break;
      }
    }
    if (flag == 1) {
      cout << "YES";
      return 0;
    }
    cout << "NO";
  }
  return 0;
}
