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() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n, m, i, j;
  unordered_map<long long int, long long int> ma;
  cin >> n >> m;
  long long int point1, point2;
  long long int a1[300005], a2[300005];
  for (i = 0; i < m; i++) {
    cin >> a1[i] >> a2[i];
  }
  point1 = a1[0];
  point2 = a2[0];
  long long int flag = 0;
  for (i = 1; i < m; i++) {
    if (a1[i] != point1 && a1[i] != point2 && a2[i] != point1 &&
        a2[i] != point2) {
      flag = 1;
      break;
    }
  }
  if (flag == 0) {
    cout << "YES";
    return (0);
  }
  flag = 0;
  point1 = a1[0];
  long long int cou = 0;
  for (i = 1; i < m; i++) {
    if (a1[i] != point1 && a2[i] != point1 && cou == 0) {
      point2 = a1[i];
      cou = 1;
    }
    if (a1[i] != point1 && a1[i] != point2 && a2[i] != point1 &&
        a2[i] != point2 && cou == 1) {
      flag = 1;
      break;
    }
  }
  if (flag == 0) {
    cout << "YES";
    return (0);
  }
  flag = 0;
  cou = 0;
  for (i = 1; i < m; i++) {
    if (a1[i] != point1 && a2[i] != point1 && cou == 0) {
      point2 = a2[i];
      cou = 1;
    }
    if (a1[i] != point1 && a1[i] != point2 && a2[i] != point1 &&
        a2[i] != point2 && cou == 1) {
      flag = 1;
      break;
    }
  }
  if (flag == 0) {
    cout << "YES";
    return (0);
  }
  flag = 0;
  point1 = a2[0];
  cou = 0;
  for (i = 1; i < m; i++) {
    if (a1[i] != point1 && a2[i] != point1 && cou == 0) {
      point2 = a1[i];
      cou = 1;
    }
    if (a1[i] != point1 && a1[i] != point2 && a2[i] != point1 &&
        a2[i] != point2 && cou == 1) {
      flag = 1;
      break;
    }
  }
  if (flag == 0) {
    cout << "YES";
    return (0);
  }
  flag = 0;
  cou = 0;
  for (i = 1; i < m; i++) {
    if (a1[i] != point1 && a2[i] != point1 && cou == 0) {
      point2 = a2[i];
      cou = 1;
    }
    if (a1[i] != point1 && a1[i] != point2 && a2[i] != point1 &&
        a2[i] != point2 && cou == 1) {
      flag = 1;
      break;
    }
  }
  if (flag == 0) {
    cout << "YES";
    return (0);
  }
  cout << "NO";
}
