#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <math.h>
#include <cmath>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <iomanip>
#include <climits>
#include <functional>
#include <cassert>
#include <tuple>
using namespace std;
using ll = long long;

int N, M;
vector<int> G[101];

int main() {

    cin >> N >> M;
    for(int i = 0; i < M; ++i) {
        int a,b; cin >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }

    vector<int> vis(N+1, -1);

    for(int i = 1; i <= N; ++i) {
        if(vis[i] != -1) continue;
        queue<int> q;
        q.push(i);
        vis[i] = 0;
        while(!q.empty()) {
            int p = q.front(); q.pop();
            int n = vis[p];
            for(int ne : G[p]) {
                if(vis[ne] == 1-n) continue;
                else if(vis[ne] == n) {
                    cout << "No" << endl;
                    return 0;
                }
                
                vis[ne] = 1-n;
                q.push(ne);
            }
        }
    }

    cout << "Yes" << endl;

}