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 int maxn = 4e5 + 5;
int a[maxn][3];
bool vis1[maxn], vis2[maxn];
int main() {
  int n, m;
  bool flag = true;
  scanf("%d%d", &n, &m);
  scanf("%d%d", &a[1][1], &a[1][2]);
  vis1[1] = vis2[1] = 1;
  for (int i = 2; i <= m; i++) {
    scanf("%d%d", &a[i][1], &a[i][2]);
    if (a[i][1] == a[1][1] || a[i][2] == a[1][1]) vis1[i] = 1;
    if (a[i][1] == a[1][2] || a[i][2] == a[1][2]) vis2[i] = 1;
  }
  int t1, t2;
  for (int i = 2; i <= m; i++) {
    if (!vis1[i]) {
      t1 = a[i][1];
      t2 = a[i][2];
      break;
    }
  }
  for (int i = 1; i <= m; i++) {
    if (!vis1[i] && a[i][1] != t1 && a[i][2] != t1) {
      flag = false;
      break;
    }
  }
  if (flag) {
    cout << "YES";
    return 0;
  }
  flag = true;
  for (int i = 1; i <= m; i++) {
    if (!vis1[i] && a[i][1] != t2 && a[i][2] != t2) {
      flag = false;
      break;
    }
  }
  if (flag) {
    cout << "YES";
    return 0;
  }
  flag = true;
  for (int i = 2; i <= m; i++) {
    if (!vis2[i]) {
      t1 = a[i][1];
      t2 = a[i][2];
      break;
    }
  }
  for (int i = 1; i <= m; i++) {
    if (!vis2[i] && a[i][1] != t1 && a[i][2] != t1) {
      flag = false;
      break;
    }
  }
  if (flag) {
    cout << "YES";
    return 0;
  }
  flag = true;
  for (int i = 1; i <= m; i++) {
    if (!vis2[i] && a[i][1] != t2 && a[i][2] != t2) {
      flag = false;
      break;
    }
  }
  if (flag) {
    cout << "YES";
    return 0;
  }
  cout << "NO";
  return 0;
}
