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

#define rep(i, a, b) for (int i = a; i < b; i++)
using ll = long long;

int main(){
    int n, m;
    cin >> n >> m;
    vector<vector<int>> g(n);
    rep(i, 0, m) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    vector<int> v(n, -1);
    rep(i, 0, n) {
        if(v[i] >= 0) continue;
        queue<int> q;
        v[i] = 0;
        q.push(i);
        while(q.size()) {
            int u = q.front();
            q.pop();
            int c = v[u];
            for(int e : g[u]) {
                if(v[e] >= 0) {
                    if(v[e] == c) {
                        cout << "No" << endl;
                        return 0;
                    }
                }
                else {
                    v[e] = 1 - c;
                    q.push(e);
                }
            }
        }
    }
    cout << "Yes" << endl;
}