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>
long long powermod(long long _a, long long _b, long long _m) {
  long long _r = 1;
  while (_b) {
    if (_b % 2 == 1) _r = (_r * _a) % _m;
    _b /= 2;
    _a = (_a * _a) % _m;
  }
  return _r;
}
using namespace std;
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  long long n, m;
  cin >> n >> m;
  pair<long long, long long> arr[m];
  for (long long i = 0; i < m; ++i) cin >> arr[i].first >> arr[i].second;
  bool flag1[m];
  memset(flag1, false, sizeof(flag1));
  ;
  long long temp = arr[0].first;
  long long megaflag = 0;
  for (long long i = 0; i < m; ++i) {
    if (arr[i].first == temp || arr[i].second == temp) flag1[i] = true;
  }
  long long f2 = 2;
  for (long long i = 0; i < m; ++i) {
    if (flag1[i] == false) {
      f2 = 0;
      temp = arr[i].first;
      for (long long j = i; j < m; j++) {
        if (flag1[j] == false)
          if (arr[j].first != temp && arr[j].second != temp) {
            f2 = 1;
          }
      }
      if (f2 == 0) {
        megaflag = 1;
      }
      f2 = 0;
      temp = arr[i].second;
      for (long long j = i; j < m; j++) {
        if (flag1[j] == false)
          if (arr[j].first != temp && arr[j].second != temp) {
            f2 = 1;
          }
      }
      if (f2 == 0) {
        megaflag = 1;
      }
      break;
    }
  }
  if (f2 == 2) {
    megaflag = 1;
  }
  temp = arr[0].second;
  memset(flag1, false, sizeof(flag1));
  ;
  for (long long i = 0; i < m; ++i) {
    if (arr[i].first == temp || arr[i].second == temp) flag1[i] = true;
  }
  f2 = 2;
  for (long long i = 0; i < m; ++i) {
    if (flag1[i] == false) {
      f2 = 0;
      temp = arr[i].first;
      for (long long j = i; j < m; j++) {
        if (flag1[j] == false)
          if (arr[j].first != temp && arr[j].second != temp) {
            f2 = 1;
          }
      }
      if (f2 == 0) {
        megaflag = 1;
      }
      f2 = 0;
      temp = arr[i].second;
      for (long long j = i; j < m; j++) {
        if (flag1[j] == false)
          if (arr[j].first != temp && arr[j].second != temp) {
            f2 = 1;
          }
      }
      if (f2 == 0) {
        megaflag = 1;
      }
      break;
    }
  }
  if (f2 == 2) {
    megaflag = 1;
  }
  if (megaflag == 1)
    cout << "YES";
  else
    cout << "NO";
}
