#include <bits/stdc++.h>
//#include <atcoder/modint>
using namespace std;
//using namespace atcoder;
//using mint = modint998244353;
#define rep(i,n) for(long long i=0;i<n;i++)
#define rep1(i,n) for(long long i=1;i<=n;i++)
#define Rep(i,a,b) for(long long i=a;i<=b;i++)
#define all(a) (a).begin(), (a).end()
#define fst first
#define snd second
typedef unsigned long long ull;
typedef long long ll;
typedef vector<int> vec;
typedef vector<vector<int>> vvec;
typedef vector<long long> vecll;
typedef vector<vector<long long>> vvecll;

//#include<boost/multiprecision/cpp_int.hpp>
//using namespace boost::multiprecision;

const ll mod=998244353;
//const ll mod=1e9+7;
const ll INF=5e18;
const int INT_INF=1e9+100;
const double pi=3.14159265358979;

//xのn乗をpで割ったあまりを求める
ll modpow(ll x,ll n,ll p=mod){
  if(n==0) return 1;
  if(n%2==1) return (x*modpow(x,n-1,p))%p;
  else{
    ll t=modpow(x,n/2,p);
    assert(t>0);
    return (t*t)%p;
  }
}

//xの逆元(p:素数)
ll inv(ll x,ll p=mod){
  return modpow(x,p-2,p);
}

template <typename T>
int index(vector<T> &a, T x){
	return lower_bound(all(a),x)-a.begin();
}


int main(){
	int n,m;
  cin >> n >> m;
  vvec g(n+1,vec());
  rep(i,m){
    int a,b;
    cin >> a >> b;
    g[a].push_back(b);
    g[b].push_back(a);
  }
  vec color(n+1,-1);
  bool ans=true;
  rep1(i,n){
    if(color[i]!=-1) continue;
    color[i]=0;
    queue<int> q;
    q.push(i);
    while(!q.empty()){
      int x=q.front();
      q.pop();
      for(int y:g[x]){
        if(color[y]==-1){
          color[y]=color[x]^1;
          q.push(y);
        }else{
          ans&=(color[x]!=color[y]);
        }
      }
    }
  }
  cout << (ans?"Yes":"No") << endl;
	return 0;
}