#include <bits/stdc++.h>
using namespace std;
inline long long get_num(char ch) {
  if (ch == '-')
    return 0;
  else if (ch >= 'a' && ch <= 'z') {
    return 1 + (ch - 'a');
  } else if (ch >= 'A' && ch <= 'Z') {
    return 27 + (ch - 'A');
  } else if (ch >= '0' && ch <= '9') {
    return 53 + (ch - '0');
  }
}
int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};
inline int GA(long long n, vector<long long>& vec) {
  for (int i = 0; i < n; ++i) {
    long long x;
    cin >> x;
    vec.push_back(x);
  }
  return 0;
}
inline int GAEG(long long m, vector<long long> vec[]) {
  for (int i = 0; i < m; ++i) {
    long long x, y;
    cin >> x >> y;
    x--, y--;
    vec[x].push_back(y);
    vec[y].push_back(x);
  }
  return 0;
}
const long long MD = 1000000007;
bool isvalid(long long xx, long long yy, long long n, long long m) {
  return (xx >= 0 && xx < n && yy >= 0 && yy < m);
}
long long pw(long long x, long long y, long long dr) {
  if (y == 0) return 1;
  long long o = y / 2;
  long long f = pw(x, o, dr) % dr;
  if (y % 2) {
    return (((f * f) % dr) * x) % dr;
  } else
    return (f * f) % dr;
}
vector<pair<long long, long long> > v;
map<long long, long long> mp;
long long n, m;
long long FF(long long x) {
  mp.clear();
  long long p = 0;
  for (auto i : v) {
    if (i.first == x || i.second == x) {
      p++;
      continue;
    }
    mp[i.first]++;
    if (i.first != i.second) mp[i.second]++;
  }
  for (auto i : mp) {
    long long qq = p + i.second;
    if (qq == m) return 1;
  }
  if (p == m) return 1;
  return 0;
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < m; ++i) {
    long long x, y;
    cin >> x >> y;
    v.push_back(make_pair(x, y));
  }
  if (FF(v[0].first) || FF(v[0].second)) {
    cout << "yes" << endl;
  } else
    cout << "no" << endl;
  return 0;
}
