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>
class BPairs {
 public:
  void solve(std::istream& in, std::ostream& out) {
    int n, m;
    in >> n >> m;
    std::vector<std::pair<int, int> > pairs(m);
    for (int i = 0; i < m; ++i) {
      int a, b;
      in >> a >> b;
      pairs[i] = std::pair<int, int>(a, b);
    }
    int a = pairs[0].first;
    int b = pairs[0].second;
    int c, d;
    bool found = false;
    for (int i = 1; i < m; ++i) {
      c = pairs[i].first;
      d = pairs[i].second;
      if (c != a && c != b && d != a && d != b) {
        found = true;
        break;
      }
    }
    if (!found) {
      out << "YES";
      return;
    }
    std::vector<std::pair<int, int> > options = {
        std::pair<int, int>(a, c), std::pair<int, int>(a, d),
        std::pair<int, int>(b, c), std::pair<int, int>(b, d)};
    for (auto it = options.begin(); it != options.end(); ++it) {
      a = it->first;
      b = it->second;
      bool ok = true;
      for (int i = 0; i < m; ++i) {
        c = pairs[i].first;
        d = pairs[i].second;
        if (!(a == c || a == d || b == c || b == d)) {
          ok = false;
          break;
        }
      }
      if (ok) {
        out << "YES";
        return;
      }
    }
    out << "NO";
  }
};
int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(NULL);
  std::cout << std::fixed;
  std::cout << std::setprecision(15);
  BPairs solver;
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solver.solve(in, out);
  return 0;
}
