#include <bits/stdc++.h>
using namespace std;

int main(){
  int n,m;
  cin >> n >> m;
  vector<set<int>> to(n);
  for(int i=0;i<m;i++){
    int a,b;
    cin >> a >> b;
    a--; b--;
    to.at(a).insert(b);
    to.at(b).insert(a);
  }
  queue<int> q;
  vector<int> seen(n, -1);
  for(int i=0;i<n;i++){
    if(seen.at(i) < 0){
      seen.at(i) = 0;
      q.push(i);
      while(!q.empty()){
        int p = q.front();
        q.pop();
        for(int j : to.at(p)){
          if(seen.at(j) < 0){
            seen.at(j) = seen.at(p) ^ 1;
            q.push(j);
          }else{
            if(seen.at(j) != (seen.at(p) ^ 1)){
              cout << "No" << endl;
              return 0;
            }
          }
        }
      }
    }
  }
  cout << "Yes" << endl;
}