#include <iostream>
#include <cstring>
using namespace std;
const int N = 1E5 + 10;
int head[N], value[N*2], nxt[N*2];
int idx;
int n, m;
void add(int a, int b){
    value[idx] = b;
    nxt[idx] = head[a];
    head[a] = idx ++ ;
}
void read(){
    memset(head, -1, sizeof head);
    cin >> n >> m;
    int a, b;
    while(m -- ){
        scanf("%d%d", &a, &b);
        add(a, b), add(b, a);
    }
}
int color[N];
bool dfs(int u, int c){
    color[u] = c;
    for(int i = head[u]; i != -1; i = nxt[i]){
        int p = value[i];
        if(!color[p]){
            if(!dfs(p, 3 - c))  return false;
        }else{
            if(color[p] == c)   return false;
        }
    }
    return true;
}
int main(){
    read();
    bool res = true;
    for(int i = 1; i <= n; i ++ ){
        if(!color[i]){
            if(!dfs(i, 1)){
                res = false;
                break;
            }
        }
    }
    if(res) cout << "Yes" << endl;
    else    cout << "No" << endl;
    return 0;
}