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>
int main() {
  size_t n, m;
  std::cin >> n >> m;
  std::vector<std::pair<size_t, size_t>> pairs(m);
  size_t a, b, val1, val2;
  std::cin >> val1 >> val2;
  size_t n_1 = 1, n_2 = 1;
  pairs[0] = {val1, val2};
  for (size_t i = 1; i != m; ++i) {
    std::cin >> a >> b;
    pairs[i] = {a, b};
    if (a == val1 || b == val1) n_1++;
    if (b == val1 || b == val2) n_2++;
  }
  if (n_1 == m || n_2 == m) {
    std::cout << "YES\n";
  } else {
    bool flag = true;
    std::pair<size_t, size_t> temp = {0, 0};
    size_t time = 1;
    for (size_t i = 1; i != m; ++i) {
      if (pairs[i].first != val1 && pairs[i].second != val1 && time == 1) {
        temp = pairs[i];
        time++;
      } else if (pairs[i].first != val1 && pairs[i].second != val1 &&
                 time == 2) {
        if (pairs[i].first != temp.first && pairs[i].second != temp.first)
          temp.first = 0;
        if (pairs[i].first != temp.second && pairs[i].second != temp.second)
          temp.second = 0;
        if (temp.first == 0 && temp.second == 0) flag = false;
      }
      if (!flag) break;
    }
    if (flag) {
      std::cout << "YES\n";
    } else {
      flag = true;
      temp = {0, 0};
      time = 1;
      for (size_t i = 1; i != m; ++i) {
        if (pairs[i].first != val2 && pairs[i].second != val2 && time == 1) {
          temp = pairs[i];
          time++;
        } else if (pairs[i].first != val2 && pairs[i].second != val2 &&
                   time == 2) {
          if (pairs[i].first != temp.first && pairs[i].second != temp.first)
            temp.first = 0;
          if (pairs[i].first != temp.second && pairs[i].second != temp.second)
            temp.second = 0;
          if (temp.first == 0 && temp.second == 0) flag = false;
        }
        if (!flag) break;
      }
      if (flag)
        std::cout << "YES\n";
      else
        std::cout << "NO\n";
    }
  }
}
