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 cnt[300001] = {};
int cnt1[300001] = {};
int arr[300000][2];
int main() {
  int n;
  cin >> n;
  int m;
  cin >> m;
  for (int i = 0; i < m; i++) {
    cin >> arr[i][0] >> arr[i][1];
  }
  vector<pair<int, int>> v;
  for (int i = 1; i <= m - 1; i++) {
    if (arr[i][0] != arr[0][0] && arr[i][1] != arr[0][0]) {
      v.push_back({arr[i][0], arr[i][1]});
    }
  }
  int mx = 0;
  for (int i = 0; i < v.size(); i++) {
    cnt[v[i].first]++;
    mx = max(mx, cnt[v[i].first]);
    cnt[v[i].second]++;
    mx = max(mx, cnt[v[i].second]);
  }
  if (mx == v.size() || v.size() == 0) {
    cout << "YES"
         << "\n";
    return 0;
  }
  vector<pair<int, int>> v1;
  for (int i = 1; i <= m - 1; i++) {
    if (arr[i][0] != arr[0][1] && arr[i][1] != arr[0][1]) {
      v1.push_back({arr[i][0], arr[i][1]});
    }
  }
  int mx1 = 0;
  for (int i = 0; i < v1.size(); i++) {
    cnt1[v1[i].first]++;
    mx1 = max(mx1, cnt1[v1[i].first]);
    cnt1[v1[i].second]++;
    mx1 = max(mx1, cnt1[v1[i].second]);
  }
  if (mx1 == v1.size() || v1.size() == 0) {
    cout << "YES"
         << "\n";
    return 0;
  }
  cout << "NO";
  return 0;
}
