#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

struct UnionFind{
    vector<ll> parent;
    vector<ll> sizes;
    
    UnionFind(ll N) : parent(N), sizes(N, 1){
        rep(i, N) parent[i] = i;
    }
    
    ll root(ll x){
        if (parent[x] == x) return x;
        return parent[x] = root(parent[x]);
    }
 
    void unite(ll x, ll y){
        ll rx = root(x);
        ll ry = root(y);
        if (rx == ry) return;
        if (sizes[rx] < sizes[ry]) swap(rx, ry);
        sizes[rx] += sizes[ry];
        parent[ry] = rx;
    }
 
    bool same(ll x, ll y){
        ll rx = root(x);
        ll ry = root(y);
        return rx == ry;
    }
 
    ll size(ll x){
        return sizes[root(x)];
    }
};

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    ll n, m;
    cin >> n >> m;

    UnionFind UF(2*n);
    rep(i, m){
        ll a, b;
        cin >> a >> b;
        a--; b--;
        UF.unite(a, n+b);
        UF.unite(n+a, b);
    }

    bool flag = true;
    rep(i, n){
        if(!UF.same(i, n+i)) flag = false;
    }

    if(flag) cout << "Yes" << endl;
    else cout << "No" << endl;
}