#include <bits/stdc++.h>
using namespace std;
inline int two(int n) { return 1 << n; }
inline int test(int n, int b) { return (n >> b) & 1; }
inline void set_bit(int& n, int b) { n |= two(b); }
inline void unset_bit(int& n, int b) { n &= ~two(b); }
inline int last_bit(int n) { return n & (-n); }
inline int ones(int n) {
  int res = 0;
  while (n && ++res) n -= n & (-n);
  return res;
}
bool comparator(int i, int j) { return (i < j); }
long long gcd(long long x, long long y) {
  long long t;
  while (y != 0) {
    t = x % y;
    x = y;
    y = t;
  }
  return x;
}
bool isVowel(char ch) {
  if (ch == 'a' || ch == 'i' || ch == 'e' || ch == 'u' || ch == 'o' ||
      ch == 'y') {
    return true;
  }
  return false;
}
bool isPrime(int n) {
  int root = sqrt(n);
  for (int i = 2; i <= root; i++)
    if (n % i == 0) return 0;
  return 1;
}
int n, m;
pair<int, int> c[300004];
int main() {
  cin >> n >> m;
  for (int i = 0; i < m; i++) cin >> c[i].first >> c[i].second;
  int x = c[0].first;
  int cnt[300004] = {
      0,
  };
  int ans = 0;
  for (int i = 1; i < m; i++) {
    if (c[i].first == x || c[i].second == x)
      continue;
    else {
      cnt[c[i].first]++;
      cnt[c[i].second]++;
      ans++;
    }
  }
  for (int i = 0; i <= 300000; i++)
    if (cnt[i] == ans) {
      cout << "YES";
      return 0;
    }
  memset(cnt, 0, sizeof(cnt));
  ans = 0;
  x = c[0].second;
  for (int i = 1; i < m; i++) {
    if (c[i].first == x || c[i].second == x)
      continue;
    else {
      cnt[c[i].first]++;
      cnt[c[i].second]++;
      ans++;
    }
  }
  for (int i = 0; i <= 300000; i++)
    if (cnt[i] == ans) {
      cout << "YES";
      return 0;
    }
  cout << "NO";
  return 0;
}
