#include <bits/stdc++.h>
using namespace std;
#define rep(i, x, limit) for (long long i = (long long)x; i < (long long)limit; i++)
#define REP(i, x, limit) for (long long i = (long long)x; i <= (long long)limit; i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define el '\n'
#define spa " "
#define Yes cout << "Yes" << el
#define No cout << "No" << el
#define YES cout << "YES" << el
#define NO cout << "NO" << el
#define eps (1e-10)
#define Equals(a,b) (fabs((a) - (b)) < eps )
#define debug(x) cerr << #x << " = " << x << el
using ll = long long;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vs = vector<string>;
using vb = vector<bool>;
const double pi = 3.141592653589793238;
const int inf = 1073741823;
const ll infl = 1LL << 60;
const string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string abc = "abcdefghijklmnopqrstuvwxyz";
const ll MOD = 998244353;
#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using vm = vector<mint>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll n,m;cin>>n>>m;
  vvl G(n);
  rep(i,0,m){
    ll a,b;cin>>a>>b;
    a--;b--;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  vi P(n,-1);
  rep(i,0,n){
    if(P[i]!=-1)continue;
    queue<ll> Q;
    Q.push(i);
    P[i]=0;
    while(!Q.empty()){
      ll v=Q.front();Q.pop();
      for(auto to:G[v]){
        if(P[to]==-1){
          P[to]=P[v]^1;
          Q.push(to);
        }else if(P[to]==P[v]){
          No;
          return 0;
        }
      }
    }
  }
  Yes;
}