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;
long long binpow(long long a, long long n) {
  long long res = 1;
  while (n) {
    if (n & 1) res = (res * a);
    a = (a * a);
    n >>= 1;
  }
  return res;
}
vector<int> z_function(string s) {
  size_t n = (int)s.length();
  vector<int> z(n);
  for (int i = 1, l = 0, r = 0; i < n; ++i) {
    if (i <= r) z[i] = min(r - i + 1, z[i - l]);
    while (i + z[i] < n && s[z[i]] == s[i + z[i]]) ++z[i];
    if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;
  }
  return z;
}
int main() {
  int n, m;
  cin >> n >> m;
  vector<pair<int, int> > v(m);
  vector<bool> ch(m, 0), sav;
  for (int i = 0; i < m; i++) {
    int l, r;
    cin >> l >> r;
    v[i].first = min(l, r);
    v[i].second = max(l, r);
  }
  const int first1 = v[0].first;
  const int first2 = v[0].second;
  for (int i = 0; i < m; i++) {
    if (first1 == v[i].first || first1 == v[i].second) {
      ch[i] = 1;
    }
  }
  sav = ch;
  bool ans = 0;
  int second1 = -1;
  int second2 = -1;
  for (int i = 0; i < m; i++) {
    if (ch[i] == 0) {
      second1 = v[i].first;
      second2 = v[i].second;
      break;
    }
  }
  for (int i = 0; i < m; i++) {
    if (second1 == v[i].first || second1 == v[i].second) {
      ch[i] = 1;
    }
  }
  for (int i = 0; i < m; i++) {
    ans = 1;
    if (ch[i] == 0) {
      ans = 0;
      break;
    }
  }
  if (ans) {
    cout << "YES";
    return 0;
  }
  ch = sav;
  for (int i = 0; i < m; i++) {
    if (second2 == v[i].first || second2 == v[i].second) {
      ch[i] = 1;
    }
  }
  for (int i = 0; i < m; i++) {
    ans = 1;
    if (ch[i] == 0) {
      ans = 0;
      break;
    }
  }
  if (ans) {
    cout << "YES";
    return 0;
  }
  ch = vector<bool>(m, 0);
  for (int i = 0; i < m; i++) {
    if (first2 == v[i].first || first2 == v[i].second) {
      ch[i] = 1;
    }
  }
  sav = ch;
  int second12 = -1;
  int second22 = -1;
  for (int i = 0; i < m; i++) {
    if (ch[i] == 0) {
      second1 = v[i].first;
      second2 = v[i].second;
      break;
    }
  }
  for (int i = 0; i < m; i++) {
    if (second1 == v[i].first || second1 == v[i].second) {
      ch[i] = 1;
    }
  }
  for (int i = 0; i < m; i++) {
    ans = 1;
    if (ch[i] == 0) {
      ans = 0;
      break;
    }
  }
  if (ans) {
    cout << "YES";
    return 0;
  }
  ch = sav;
  for (int i = 0; i < m; i++) {
    if (second2 == v[i].first || second2 == v[i].second) {
      ch[i] = 1;
    }
  }
  for (int i = 0; i < m; i++) {
    ans = 1;
    if (ch[i] == 0) {
      ans = 0;
      break;
    }
  }
  if (ans) {
    cout << "YES";
    return 0;
  }
  cout << "NO";
  return 0;
}
