#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<int(n); ++i)
#define repll(i,m,n) for(ll i=m; i<ll(n); ++i)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define fi first
#define se second

template<typename T> bool chmin(T& a, T b){ if(a > b){a = b; return true;} return false; }
template<typename T> bool chmax(T& a, T b){ if(a < b){a = b; return true;} return false; }

template<typename T> T gcd(T a, T b){ return a % b ? gcd(b, a % b) : b; }
template<typename T> T lcm(T a, T b){ return a / gcd(a, b) * b; }

struct UnionFind{
    vector<int> siz, parent;

    UnionFind(){}
    UnionFind(int n){
        siz.resize(n, 0);
        parent.resize(n, 0);
        for(int i=0; i<n; ++i){
            make_tree(i);
        }
    }

    void make_tree(int x){
        parent[x] = x;
        siz[x] = 1;
    }

    bool is_same(int x, int y){
        return find_root(x) == find_root(y);
    }

    bool unite(int x, int y){
        x = find_root(x);
        y = find_root(y);
        if(x == y) return false;
        if(siz[x] > siz[y]){
            parent[y] = x;
            siz[x] += siz[y];
        }else{
            parent[x] = y;
            siz[y] += siz[x];
        }
        return true;
    }

    int find_root(int x){
        if(x != parent[x]) parent[x] = find_root(parent[x]);
        return parent[x];
    }

    int tree_size(int x){
        return siz[find_root(x)];
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, M;
    cin >> N >> M;

    UnionFind UF(2*N + 1);
    rep(i, 0, M){
        int a, b;
        cin >> a >> b;
        UF.unite(a, b + N);
        UF.unite(a + N, b);
    }

    string ans = "Yes";
    rep(i, 1, N+1){
        if(!UF.is_same(i, i+N)){
            ans = "No";
            break;
        }
    }
    cout << ans << endl;

    return 0;
}