#include <bits/stdc++.h>
using namespace std;
long long mul(long long a, long long b) {
  return (a % 1000000007 * b % 1000000007) % 1000000007;
}
long long add(long long a, long long b) {
  return (a % 1000000007 + b % 1000000007) % 1000000007;
}
long long powftn(long long a, long long b) {
  if (a == 1 || !b) {
    return 1;
  }
  long long tmp = powftn(a, b / 2);
  tmp = mul(tmp, tmp);
  if (b & 1) {
    tmp = mul(tmp, a);
  }
  return tmp;
}
long long modinv(long long a) { return powftn(a, 1000000007 - 2) % 1000000007; }
long long gcd(long long a, long long b) {
  if (!b) {
    return a;
  }
  return gcd(b, a % b);
}
long long lcm(long long a, long long b) {
  if (!a || !b) {
    return 0;
  }
  return (a * b) / gcd(a, b);
}
int i, j, k, n, m, q, t;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  vector<pair<int, int> > v;
  for (i = 0; i < m; i++) {
    int u, v1;
    cin >> u >> v1;
    v.push_back({u, v1});
  }
  vector<int> f(n + 3, 0);
  int a = v[0].first, c1 = 0, c, d, flag = 0, b = v[0].second;
  for (auto u : v) {
    if (u.first == a || u.second == a)
      c1++;
    else {
      f[u.first]++;
      f[u.second]++;
      if (!flag) {
        flag = 1;
        c = u.first;
        d = u.second;
      }
    }
  }
  int rem = m - c1;
  if (!flag || (f[c] == rem || f[d] == rem)) {
    cout << "YES\n";
    return 0;
  }
  fill(f.begin(), f.end(), 0);
  flag = 0;
  c1 = 0;
  for (auto u : v) {
    if (u.first == b || u.second == b)
      c1++;
    else {
      f[u.first]++;
      f[u.second]++;
      if (!flag) {
        flag = 1;
        c = u.first;
        d = u.second;
      }
    }
  }
  rem = m - c1;
  if (!flag || (f[c] == rem || f[d] == rem)) {
    cout << "YES\n";
    return 0;
  }
  cout << "NO\n";
  return 0;
}
