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;
void solve() {
  long long n, m, i, j, x, y, a, b, c, f = 0;
  cin >> n >> m;
  cin >> x >> y;
  vector<pair<long long, long long> > v, w;
  v.push_back(make_pair(x, y));
  a = x;
  c = y;
  f = 0;
  for (i = 1; i < m; ++i) {
    cin >> x >> y;
    v.push_back(make_pair(x, y));
    if (x != a && y != a) {
      f = 1;
      w.push_back(make_pair(x, y));
    }
  }
  if (f == 0) {
    cout << "YES";
    return;
  }
  b = w[0].first;
  f = 0;
  for (i = 1; i < w.size(); i++) {
    if (w[i].first != b && w[i].second != b) {
      f = 1;
      break;
    }
  }
  if (f == 0) {
    cout << "YES";
    return;
  }
  b = w[0].second;
  f = 0;
  for (i = 1; i < w.size(); i++) {
    if (w[i].first != b && w[i].second != b) {
      f = 1;
      break;
    }
  }
  if (f == 0) {
    cout << "YES";
    return;
  }
  f = 0;
  a = c;
  w.clear();
  for (i = 1; i < v.size(); ++i) {
    if (v[i].first != a && v[i].second != a) {
      w.push_back(make_pair(v[i].first, v[i].second));
    }
  }
  if (w.size() == 0) {
    cout << "YES";
    return;
  }
  b = w[0].first;
  for (i = 1; i < w.size(); i++) {
    if (w[i].first != b && w[i].second != b) {
      f = 1;
      break;
    }
  }
  if (f == 0) {
    cout << "YES";
    return;
  }
  b = w[0].second;
  f = 0;
  for (i = 1; i < w.size(); i++) {
    if (w[i].first != b && w[i].second != b) {
      f = 1;
      break;
    }
  }
  if (f == 0) {
    cout << "YES";
    return;
  }
  cout << "NO";
  return;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}
