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;
const long long N = 3e5 + 5;
long long a[N + 5], b[N + 5], cnt[N + 5];
long long n, m;
bool solv(long long x) {
  long long bc = 0;
  memset(cnt, 0, sizeof(cnt));
  for (long long i = 1; i <= m; i++) {
    if (a[i] == x || b[i] == x) {
      continue;
    }
    ++bc;
    ++cnt[a[i]], ++cnt[b[i]];
  }
  for (long long i = 1; i <= n; i++) {
    if (cnt[i] == bc) return 1;
  }
  return 0;
}
int32_t main() {
  cin >> n >> m;
  for (long long i = 1; i <= m; i++) {
    cin >> a[i] >> b[i];
  }
  bool ans = solv(a[1]);
  ans |= solv(b[1]);
  cout << ((ans) ? "YES" : "NO");
  return 0;
}
