#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;

#define rep(i,n) for(ll i=0;i<n;++i)
#define all(a) (a).begin(),(a).end()
ll intpow(ll a, ll b){ ll ans = 1; while(b){ if(b & 1) ans *= a; a *= a; b /= 2; } return ans; }
ll modpow(ll a, ll b, ll p){ ll ans = 1; while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }
template<class T> T div_floor(T a, T b) { return a / b - ((a ^ b) < 0 && a % b); }
template<class T> T div_ceil(T a, T b) { return a / b + ((a ^ b) > 0 && a % b); }
template <typename T, typename U> inline bool chmin(T &x, U y) { return (y < x) ? (x = y, true) : false; }
template <typename T, typename U> inline bool chmax(T &x, U y) { return (x < y) ? (x = y, true) : false; }

template<typename T>
ostream &operator<<(ostream &os, const vector<T> &a){
    if (a.empty()) return os;
    os << a.front();
    for (auto e : a | views::drop(1)){
        os << ' ' << e;
    }
    return os;
}

void dump(auto ...vs){
    ((cout << vs << ' '), ...) << endl;
}

#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;

void solve() {
    ll N,M,K;
    cin>>N>>M>>K;
    scc_graph sc(N);
    vector<pair<ll,ll>> el;
    rep(i,M){
        ll u,v;
        cin>>u>>v;
        u--;
        v--;
        el.emplace_back(u,v);
        sc.add_edge(u,v);
    }
    vector<vector<int>> grp=sc.scc();
    vector<ll> gn(N);
    ll S=grp.size();
    rep(i,S-1){
        if (grp[i].size()==1 and grp[i+1].size()==1){
            cout<<"No"<<'\n';
            return;
        }
    }
    rep(i,S){
        for (int v:grp[i]){
            gn[v]=i;
        }
    }
    vector<vector<ll>> edge(N);
    vector<bool> con(S-1,false);
    for (auto [u,v]:el){
        if (gn[u]==gn[v]){
            edge[u].push_back(v);
        }
        else{
            if (gn[v]==gn[u]+1){
                con[gn[u]]=true;
            }
        }
    }
    rep(i,S-1){
        if (!con[i]){
            cout<<"No"<<'\n';
            return;
        }
    }
    vector<int> color(N,-1);
    rep(i,N){
        if (color[i]!=-1)continue;
        color[i]=0;
        if (edge[i].size()==0)continue;
        bool flag=false;
        stack<ll> st;
        st.push(i);
        while (st.size()>0){
            ll cp=st.top();st.pop();
            for (ll np:edge[cp]){
                if (color[np]!=-1){
                    if (color[np]==color[cp]){
                        flag=true;
                    }
                }
                else{
                    color[np]=color[cp]^1;
                    st.push(np);
                }
            }
        }
        if (!flag){
            cout<<"No"<<'\n';
            return;
        }
    }
    cout<<"Yes"<<'\n';
    return;
}


int main() {
    cin.tie(0)->sync_with_stdio(0);
    ll T=1;
    while (T--){
        solve();
    }
    return 0;
}