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;
  pair<int, int> a[m];
  for (int i = 0; i < m; i++) {
    int x, y;
    cin >> x >> y;
    if (y < x) swap(x, y);
    a[i] = make_pair(x, y);
  }
  sort(a, a + m);
  int y = -1;
  for (int i = 1; i < m; i++) {
    if (!(a[i].first == a[0].first || a[i].first == a[0].second ||
          a[i].second == a[0].second || a[i].second == a[0].first)) {
      y = i;
    }
  }
  if (y == -1) {
    cout << "YES";
    return 0;
  }
  int x1 = a[0].first;
  int y1 = a[y].first;
  bool f = 1;
  for (int i = 1; i < m; i++) {
    if (i != y) {
      if (!(x1 == a[i].first || x1 == a[i].second || y1 == a[i].first ||
            y1 == a[i].second)) {
        f = 0;
        break;
      }
    }
  }
  if (!f) {
    f = 1;
    x1 = a[0].first;
    y1 = a[y].second;
    for (int i = 1; i < m; i++) {
      if (i != y) {
        if (!(x1 == a[i].first || x1 == a[i].second || y1 == a[i].first ||
              y1 == a[i].second)) {
          f = 0;
          break;
        }
      }
    }
  }
  if (!f) {
    f = 1;
    x1 = a[0].second;
    y1 = a[y].first;
    for (int i = 1; i < m; i++) {
      if (i != y) {
        if (!(x1 == a[i].first || x1 == a[i].second || y1 == a[i].first ||
              y1 == a[i].second)) {
          f = 0;
          break;
        }
      }
    }
  }
  if (!f) {
    f = 1;
    x1 = a[0].second;
    y1 = a[y].second;
    for (int i = 1; i < m; i++) {
      if (i != y) {
        if (!(x1 == a[i].first || x1 == a[i].second || y1 == a[i].first ||
              y1 == a[i].second)) {
          f = 0;
          break;
        }
      }
    }
  }
  if (f) {
    cout << "YES";
  } else
    cout << "NO";
  return 0;
}
