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 N = 3e5 + 5, M = 1e9 + 7;
const unsigned long long base = 13331;
const double Pi = acos(-1.0);
const long long C = 299792458;
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
int a[N], b[N];
int h[N];
int main() {
  ios::sync_with_stdio(false);
  int n, m;
  cin >> n >> m;
  for (int i = 1; i <= m; i++) {
    cin >> a[i] >> b[i];
  }
  int x = a[1], y = b[1];
  int x1, y1;
  for (int i = 1; i <= m; i++) {
    if (a[i] == x || b[i] == x)
      continue;
    else {
      x1 = a[i], y1 = b[i];
    }
  }
  int flag = 0;
  for (int i = 1; i <= m; i++) {
    if (a[i] == x || b[i] == x || a[i] == x1 || b[i] == x1)
      continue;
    else {
      flag = 1;
      break;
    }
  }
  if (!flag) {
    cout << "YES" << endl;
    return 0;
  }
  flag = 0;
  for (int i = 1; i <= m; i++) {
    if (a[i] == x || b[i] == x || a[i] == y1 || b[i] == y1)
      continue;
    else {
      flag = 1;
      break;
    }
  }
  if (!flag) {
    cout << "YES" << endl;
    return 0;
  }
  flag = 0;
  for (int i = 1; i <= m; i++) {
    if (a[i] == x || b[i] == x || a[i] == y || b[i] == y)
      continue;
    else {
      flag = 1;
      break;
    }
  }
  if (!flag) {
    cout << "YES" << endl;
    return 0;
  }
  for (int i = 1; i <= m; i++) {
    if (a[i] == y || b[i] == y)
      continue;
    else {
      x1 = a[i], y1 = b[i];
      break;
    }
  }
  flag = 0;
  for (int i = 1; i <= m; i++) {
    if (a[i] == y || b[i] == y || a[i] == x1 || b[i] == x1)
      continue;
    else {
      flag = 1;
      break;
    }
  }
  if (!flag) {
    cout << "YES" << endl;
    return 0;
  }
  flag = 0;
  for (int i = 1; i <= m; i++) {
    if (a[i] == y || b[i] == y || a[i] == y1 || b[i] == y1)
      continue;
    else {
      flag = 1;
      break;
    }
  }
  if (!flag) {
    cout << "YES" << endl;
    return 0;
  }
  cout << "NO" << endl;
}
