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;
const long long llINF = 9223372036854775807;
const int INF = 2147483647;
const int maxn = 3e5 + 7;
const int maxm = 1e6 + 7;
const long long mod = 1e9 + 7;
const double pi = acos(-1.0);
const double eps = 1e-9;
int n, m;
set<int> s[maxn];
int st, max_deg;
int main(int argc, char const *argv[]) {
  scanf("%d%d", &n, &m);
  for (int i = 1; i <= m; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    s[u].insert(v);
    s[v].insert(u);
  }
  for (int i = 1; i <= n; i++) {
    if (s[i].size() > max_deg) {
      max_deg = s[i].size();
      st = i;
    }
  }
out1:
  for (set<int>::iterator it = s[st].begin(); it != s[st].end(); it++) {
    int to = *it;
    s[to].erase(st);
    s[st].erase(to);
    goto out1;
  }
  st = -1, max_deg = 0;
  for (int i = 1; i <= n; i++) {
    if (s[i].size() > max_deg) {
      max_deg = s[i].size();
      st = i;
    }
  }
  if (st == -1) {
    printf("YES\n");
    return 0;
  }
out2:
  for (set<int>::iterator it = s[st].begin(); it != s[st].end(); it++) {
    int to = *it;
    s[to].erase(st);
    s[st].erase(to);
    goto out2;
  }
  for (int i = 1; i <= n; i++)
    if (!s[i].empty()) {
      printf("NO\n");
      return 0;
    }
  printf("YES\n");
  return 0;
}
