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

#define pb emplace_back
#define mp make_pair
 
using ll = long long;
using pii = pair<int,int>;
 
constexpr int mod = 998244353;
constexpr int inf = 0x3f3f3f3f;
constexpr int N = 110;

int n, m, color[N];
vector<int> V[N];

bool dfs(int x){
  for(int y : V[x]){
    if(color[y]){
      if(color[y] == color[x])  return 0;
    } else {
      color[y] = 3 - color[x];
      if(!dfs(y)) return 0;
    }
  }
  return 1;
}

void _main(){
  cin >> n >> m;
  int x, y;
  while(m--){
    cin >> x >> y;
    V[x].pb(y);
    V[y].pb(x);
  }
  for(int i=1; i<=n; ++i){
    if(!color[i]){
      color[i] = 1;
      if(!dfs(i)){
        cout << "No\n";
        return;
      }
    }
  }
  cout << "Yes\n";
}

int main(){
  ios::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);
  _main();
  return 0;
}