#include <bits/stdc++.h>
using namespace std;
/*/
#include <atcoder/all>
using namespace atcoder;
//*/
#define rep(i,n) for(int i=0;i<n;i++)
#define Rep(i,a,b) for(int i=a;i<b;i++)
#define ALL(x) (x).begin(),(x).end()
#define dbgv(x); for(auto now : x) cout << now << " "; cout << endl;
//using P = pair<int,int>;
using ll = long long;
using ull = unsigned long long;
//*/
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<int> vint;

using P = pair<long long,long long>;
struct Sieve {
  int n;
  vector<int> f, primes;
  Sieve(int n=1):n(n), f(n+1) {
    f[0] = f[1] = -1;
    for (ll i = 2; i <= n; ++i) {
      if (f[i]) continue;
      primes.push_back(i);
      f[i] = i;
      for (ll j = i*i; j <= n; j += i) {
        if (!f[j]) f[j] = i;
      }
    }
  }
  bool isPrime(int x) { return f[x] == x;}
  vector<int> factorList(int x) {
    vector<int> res;
    while (x != 1) {
      res.push_back(f[x]);
      x /= f[x];
    }
    return res;
  }
  vector<P> factor(int x) {
    vector<int> fl = factorList(x);
    if (fl.size() == 0) return {};
    vector<P> res(1, P(fl[0], 0));
    for (int p : fl) {
      if (res.back().first == p) {
        res.back().second++;
      } else {
        res.emplace_back(p, 1);
      }
    }
    return res;
  }
  vector<pair<ll,int>> factor(ll x) {
    vector<pair<ll,int>> res;
    for (int p : primes) {
      int y = 0;
      while (x%p == 0) x /= p, ++y;
      if (y != 0) res.emplace_back(p,y);
    }
    if (x != 1) res.emplace_back(x,1);
    return res;
  }
} sieve(1e6);

int col[110];
void solve(){
  int n,m; cin >> n >> m;
  rep(i,110) col[i] = -1;
  vector<vint> g(n);
  rep(i,m){
    int u,v; cin>> u >> v;
    u--,v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  bool ok = true;
  auto bfs = [&](int v)->void{
    queue<int> q;
    q.push(v);
    col[v] = 0;
    while(!q.empty()){
      int now = q.front(); q.pop();
      for(int nxt : g[now]){
        if(col[nxt] == -1){
          col[nxt] = 1-col[now];
          q.push(nxt);
        }else{
          if(col[nxt] != 1-col[now]){
            ok = false;
            return;
          }
        }
      }
    }
  };
  rep(i,n){
    if(col[i] == -1) bfs(i);
  }
  if(ok) cout << "Yes" << endl;
  else cout << "No" << endl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int t = 1; //cin >> t;
  rep(_,t) solve();
}