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*/

#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <functional>
#include <set>
#include <ctime>
#include <random>
#include <chrono>
#include <cassert>
using namespace std;

namespace {
  using Integer = long long; //__int128;
  template<class T> istream& operator >> (istream& is, vector<T>& vec){for(T& val: vec) is >> val; return is;}
  template<class T> istream& operator ,  (istream& is, T& val){ return is >> val;}
  template<class T> ostream& operator << (ostream& os, const vector<T>& vec){for(int i=0; i<vec.size(); i++) os << vec[i] << (i==vec.size()-1?"":" "); return os;}
  template<class T> ostream& operator ,  (ostream& os, const T& val){ return os << " " << val;}

  template<class H> void print(const H& head){ cout << head; }
  template<class H, class ... T> void print(const H& head, const T& ... tail){ cout << head << " "; print(tail...); }
  template<class ... T> void println(const T& ... values){ print(values...); cout << endl; }

  template<class H> void eprint(const H& head){ cerr << head; }
  template<class H, class ... T> void eprint(const H& head, const T& ... tail){ cerr << head << " "; eprint(tail...); }
  template<class ... T> void eprintln(const T& ... values){ eprint(values...); cerr << endl; }

  class range{
    long long start_, end_, step_;
   public:
    struct range_iterator{
      long long val, step_;
      range_iterator(long long v, long long step) : val(v), step_(step) {}
      long long operator * (){return val;}
      void operator ++ (){val += step_;}
      bool operator != (range_iterator& x){return step_ > 0 ? val < x.val : val > x.val;}
    };
    range(long long len) : start_(0), end_(len), step_(1) {}
    range(long long start, long long end) : start_(start), end_(end), step_(1) {}
    range(long long start, long long end, long long step) : start_(start), end_(end), step_(step) {}
    range_iterator begin(){ return range_iterator(start_, step_); }
    range_iterator   end(){ return range_iterator(  end_, step_); }
  };

  string operator "" _s (const char* str, size_t size){ return move(string(str)); }
  constexpr Integer my_pow(Integer x, Integer k, Integer z=1){return k==0 ? z : k==1 ? z*x : (k&1) ? my_pow(x*x,k>>1,z*x) : my_pow(x*x,k>>1,z);}
  constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z=1){return k==0 ? z%M : k==1 ? z*x%M : (k&1) ? my_pow_mod(x*x%M,k>>1,M,z*x%M) : my_pow_mod(x*x%M,k>>1,M,z);}
  constexpr unsigned long long operator "" _ten (unsigned long long value){ return my_pow(10,value); }

  inline int k_bit(Integer x, int k){return (x>>k)&1;} //0-indexed

  mt19937 mt(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count());

  template<class T> string join(const vector<T>& v, const string& sep){
    stringstream ss; for(int i=0; i<v.size(); i++){ if(i>0) ss << sep; ss << v[i]; } return ss.str();
  }

  string operator * (string s, int k){ string ret; while(k){ if(k&1) ret += s; s += s; k >>= 1; } return ret; }

}

constexpr long long mod = 9_ten + 7;

int main(){
  int n,m;
  //cin >> n,m;
  scanf("%d%d", &n, &m);

  vector<vector<int>> G(n);
  vector<pair<int,int>> e(m);
  for(int i : range(m)){
    int u,v;
    //cin >> u,v;
    scanf("%d%d", &u, &v);
    u--; v--;
    G[u].push_back(v);
    G[v].push_back(u);
    e[i] = {min(u,v), max(u,v)};
  }

  shuffle(e.begin(), e.end(), mt);

  vector<int> dd(n, 1e7);
  for(int i : range(m)){
    if( e[i].first == 0 ) dd[ e[i].second ] = 1;
  }

  vector<vector<int>> GG(n);
  for(int i : range(m)){
    if(dd[ e[i].first ] != 1 && dd[ e[i].second ] != 1) continue;
    GG[e[i].first].push_back(e[i].second);
    GG[e[i].second].push_back(e[i].first);
  }

  auto start_time = chrono::steady_clock::now();

  for(int i : range(m)){
    if((i&255) == 0){
      auto time_now = chrono::steady_clock::now();
      if( chrono::duration_cast<chrono::milliseconds>(time_now - start_time).count() > 4000 ) break;
    }

    int u = e[i].first;
    int v = e[i].second;
    if(u == 0) continue;

    vector<int> d_u(n, 1e7);
    vector<int> d_v(n, 1e7);
    vector<int> c_u(n, 0);
    vector<int> c_v(n, 0);
    int last_v = -1;
    int last_u = -1;

    function<void(int, vector<int>&, vector<int>&, int&)> bfs = [&](int pos, vector<int>& d, vector<int>& c, int& last){
      d[pos] = 0;
      c[pos] = 1;
      queue<int> q;
      q.push(pos);
      while(q.size()){
        int p = q.front(); q.pop();
        if(d[p] >= 2) break;

        for(int nx : GG[p]){
          if(nx == u || nx == v) continue;
          bool new_v = true;
          if( (d[p] == 1 && nx == 0) || (d[p] == 0 && nx != 0) ){
            if(d[nx] == d[p]+1) new_v = false;
            d[nx] = d[p] + 1;
            c[nx] += c[p];

            if(nx == 0) last = p;
            if(nx == 0 && c[nx] >= 2){
              q = queue<int>();
              break;
            }

            if(new_v) q.push( nx );
          }
        }
      }
    };

    bfs(u, d_u, c_u, last_u);
    if(c_u[0] == 0) continue;
    bfs(v, d_v, c_v, last_v);

    if((c_u[0] >= 2 && c_v[0] >= 1) || (c_u[0] >= 1 && c_v[0] >= 2) || (c_u[0] == 1 && c_v[0] == 1 && last_u != last_v) ){
      println("YES");
      return 0;
    }
  }


  println("NO");


  return 0;
}