#include <bits/stdc++.h>
using namespace std;
using namespace std::chrono;
template <typename A>
ostream &operator<<(ostream &cout, vector<A> const &v);
template <typename A, typename B>
ostream &operator<<(ostream &cout, pair<A, B> const &p) {
  return cout << "(" << p.first << ", " << p.second << ")";
}
template <typename A>
ostream &operator<<(ostream &cout, vector<A> const &v) {
  cout << "[";
  for (int i = 0; i < v.size(); i++) {
    if (i) cout << ", ";
    cout << v[i];
  }
  return cout << "]";
}
mt19937 rng(steady_clock::now().time_since_epoch().count());
void usaco(string filename) {
#pragma message("be careful, freopen may be wrong")
  freopen((filename + ".in").c_str(), "r", stdin);
  freopen((filename + ".out").c_str(), "w", stdout);
}
const long long mod = 1e9 + 7;
long long madd(long long a, long long b) { return (a + b) % mod; }
long long msub(long long a, long long b) {
  return (((a - b) % mod) + mod) % mod;
}
long long mmul(long long a, long long b) {
  return ((a % mod) * (b % mod)) % mod;
}
long long mpow(long long base, long long exp) {
  long long res = 1;
  while (exp) {
    if (exp % 2 == 1) {
      res = (res * base) % mod;
    }
    exp >>= 1;
    base = (base * base) % mod;
  }
  return res;
}
long long minv(long long base) { return mpow(base, mod - 2); }
long long mdiv(long long a, long long b) { return mmul(a, minv(b)); }
long long gcd(long long x, long long y) {
  if (x == 0) return y;
  if (y == 0) return x;
  return gcd(y, x % y);
}
long long n, m, k, q, Q, T, l, r, x, y, z;
long long a[1000005];
long long b[1000005];
long long c[1000005];
string second, t;
long long ans = 0;
int cnt[300005];
multiset<int> rev;
bool iff = 0;
void del(int x) {
  int v = --cnt[x];
  multiset<int>::iterator it = rev.lower_bound(v + 1);
  if (it != rev.end()) rev.erase(it);
  rev.insert(v);
}
void ins(int x) {
  int v = ++cnt[x];
  multiset<int>::iterator it = rev.lower_bound(v - 1);
  if (iff || v > 1) rev.erase(it);
  rev.insert(v);
}
pair<int, int> vals[300005];
vector<int> inds[300005];
int main() {
  {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
  };
  cin >> n >> m;
  for (long long i = 0; i < m; i++) cin >> vals[i].first >> vals[i].second;
  memset(cnt, 0, sizeof(cnt));
  for (long long i = 0; i < m; i++) {
    ins(vals[i].first);
    ins(vals[i].second);
    inds[vals[i].first].push_back(i);
    inds[vals[i].second].push_back(i);
  }
  iff = 1;
  for (long long i = 1; i < n + 1; i++) {
    for (int pt : inds[i]) {
      del(vals[pt].first);
      del(vals[pt].second);
    }
    if (rev.size() && *(rev.rbegin()) >= m - inds[i].size()) {
      cout << "YES" << endl;
      exit(0);
    }
    for (int pt : inds[i]) {
      ins(vals[pt].first);
      ins(vals[pt].second);
    }
  }
  cout << "NO" << endl;
}
