#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;

bool vis[110];
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);
  }
  queue<int> q;
  q.push(0);
  col[0] = 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]){
          cout << "No" << endl;
          return;
        }
      }
    }
  }
  cout << "Yes" << endl;
}

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