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, m;
  cin >> n >> m;
  vector<pair<int, int>> v;
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    v.push_back(make_pair(a, b));
  }
  int x1 = v[0].first;
  int y1 = v[0].second;
  vector<int> p1, p2;
  for (int i = 1; i < m; i++) {
    int a = v[i].first;
    int b = v[i].second;
    if (x1 != a && x1 != b) {
      p1.push_back(i);
    }
    if (y1 != a && y1 != b) {
      p2.push_back(i);
    }
  }
  if (p1.size() == 0 || p2.size() == 0) {
    cout << "YES" << endl;
    return 0;
  }
  x1 = v[p1[0]].first;
  y1 = v[p1[0]].second;
  int c1 = 0, c2 = 0, c3 = 0, c4 = 0;
  for (int i = 1; i < p1.size(); i++) {
    int a = v[p1[i]].first;
    int b = v[p1[i]].second;
    if (x1 != a && x1 != b) {
      c1++;
    }
    if (y1 != a && y1 != b) {
      c2++;
    }
  }
  x1 = v[p2[0]].first;
  y1 = v[p2[0]].second;
  for (int i = 1; i < p2.size(); i++) {
    int a = v[p2[i]].first;
    int b = v[p2[i]].second;
    if (x1 != a && x1 != b) {
      c3++;
    }
    if (y1 != a && y1 != b) {
      c4++;
    }
  }
  if (c1 == 0 || c2 == 0) {
    cout << "YES" << endl;
  } else if (c3 == 0 || c4 == 0) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
  return 0;
}
