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() {
  int n, m;
  cin >> n >> m;
  vector<pair<int, int>> a(m);
  for (int i = 0; i < m; i++) {
    cin >> a[i].first >> a[i].second;
  }
  vector<int> member(m, 0);
  int first = a[0].first;
  member[0] = 1;
  int cnt = 1;
  for (int i = 1; i < m; i++) {
    if (a[i].first == first || a[i].second == first) {
      member[i] = 1;
      cnt++;
    }
  }
  set<int> s;
  if (cnt == m) {
    for (int i = 0; i < m; i++) {
      if (a[i].first == first) {
        s.insert(a[i].second);
      } else if (a[i].second == first) {
        s.insert(a[i].first);
      }
    }
  }
  if (s.size() == 1) {
    cout << "YES";
    return 0;
  }
  for (int j = 0; j < m; j++) {
    if (member[j] == 0) {
      int second = a[j].first;
      for (int i = 0; i < m; i++) {
        if (a[i].first == second || a[i].second == second) {
          member[i] = 1;
        }
      }
      bool check = true;
      for (int i = 0; i < m; i++) {
        if (member[i] == 0) {
          check = false;
        }
      }
      if (check) {
        cout << "YES";
        return 0;
      }
      for (int i = 0; i < m; i++) {
        if (a[i].first == second || a[i].second == second) {
          if (a[i].first != first && a[i].second != first) {
            member[i] = 0;
          }
        }
      }
      second = a[j].second;
      for (int i = 0; i < m; i++) {
        if (a[i].first == second || a[i].second == second) {
          member[i] = 1;
        }
      }
      check = true;
      for (int i = 0; i < m; i++) {
        if (member[i] == 0) {
          check = false;
        }
      }
      if (check) {
        cout << "YES";
        return 0;
      }
      break;
    }
  }
  member = vector<int>(m, 0);
  first = a[0].second;
  member[0] = 1;
  cnt = 1;
  s.clear();
  for (int i = 1; i < m; i++) {
    if (a[i].first == first || a[i].second == first) {
      member[i] = 1;
      cnt++;
    }
  }
  if (cnt == m) {
    for (int i = 0; i < m; i++) {
      if (a[i].first == first) {
        s.insert(a[i].second);
      } else if (a[i].second == first) {
        s.insert(a[i].first);
      }
    }
  }
  if (s.size() == 1) {
    cout << "YES";
    return 0;
  }
  for (int j = 0; j < m; j++) {
    if (member[j] == 0) {
      int second = a[j].first;
      for (int i = 0; i < m; i++) {
        if (a[i].first == second || a[i].second == second) {
          member[i] = 1;
        }
      }
      bool check = true;
      for (int i = 0; i < m; i++) {
        if (member[i] == 0) {
          check = false;
        }
      }
      if (check) {
        cout << "YES";
        return 0;
      }
      for (int i = 0; i < m; i++) {
        if (a[i].first == second || a[i].second == second) {
          if (a[i].first != first && a[i].second != first) {
            member[i] = 0;
          }
        }
      }
      second = a[j].second;
      for (int i = 0; i < m; i++) {
        if (a[i].first == second || a[i].second == second) {
          member[i] = 1;
        }
      }
      check = true;
      for (int i = 0; i < m; i++) {
        if (member[i] == 0) {
          check = false;
        }
      }
      if (check) {
        cout << "YES";
        return 0;
      }
      break;
    }
  }
  cout << "NO";
  return 0;
}
