#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include <map>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <stack>
#include <algorithm>
#include <array>
#include <unordered_set>
#include <unordered_map>
#include <string>
using namespace std;

bool rcmp(int a, int b) { return a>b; }
typedef long long LL;



set<int> nei[400004];
char mk[400004];
int que[400004];
int main() {
    int n, i, m, h, t, a, b;
    scanf("%d %d", &n, &m);
    for (i=0; i<n+n; i++) mk[i]=0;
    for (i=0; i<m; i++) {
        scanf("%d %d", &a, &b); a--; b--;
        nei[a*2].insert(b*2+1);
        nei[a*2+1].insert(b*2);
        nei[b*2].insert(a*2+1);
        nei[b*2+1].insert(a*2);
    }
    for (i=0; i<n+n; i+=2) if (mk[i]==0) {
        h=t=0; que[h++]=i; mk[i]=1;
        while(t<h) {
            a=que[t++];
            for (auto b: nei[a]) {
                if (mk[b]) continue;
                mk[b]=1;
                que[h++]=b;
            }
        }
        for (t=0; t<h; t++) {
            a=que[t];
            if (mk[a^1]==0) break;
        }
        if (t<h) break;
    }
    if (i<n+n) printf("No\n"); else printf("Yes\n");
    return 0;
}