#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using pll = array<ll, 2>;
using vl = vector<ll>;
template <class T> using vec = vector<T>;
template <class T> using vv = vec<vec<T>>;
template <class T> using vvv = vv<vec<T>>;
template <class T> using minpq = priority_queue<T, vector<T>, greater<T>>;
#define all(a) (a).begin(),(a).end()
#define rep(i, n) for (ll i = 0; i < (n); ++i)
#define reps(i, l, r) for(ll i = (l); i < (r); ++i)
#define rrep(i, l, r) for(ll i = (r)-1; i >= (l); --i)
#define sz(x) (ll) (x).size()
template <typename T>
bool chmax(T &a, const T& b) { return a < b ? a = b, true : false; }
template <typename T>
bool chmin(T &a, const T& b) { return a > b ? a = b, true : false; }

const ll mod = 998244353; // 1000000007;

struct mint {
    ll x;
    mint(ll y = 0) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
    mint &operator+=(const mint &p) {
        if ((x += p.x) >= mod) x -= mod;
        return *this;
    }
    mint &operator-=(const mint &p) {
        if ((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }
    mint &operator*=(const mint &p) {
        x = (ll)(1ll * x * p.x % mod);
        return *this;
    }
    mint &operator/=(const mint &p) {
        *this *= p.inv();
        return *this;
    }
    mint operator-() const { return mint(-x); }
    mint operator+(const mint &p) const { return mint(*this) += p; }
    mint operator-(const mint &p) const { return mint(*this) -= p; }
    mint operator*(const mint &p) const { return mint(*this) *= p; }
    mint operator/(const mint &p) const { return mint(*this) /= p; }
    bool operator==(const mint &p) const { return x == p.x; }
    bool operator!=(const mint &p) const { return x != p.x; }
    friend ostream &operator<<(ostream &os, const mint &p) { return os << p.x; }
    friend istream &operator>>(istream &is, mint &a) {
        ll t; is >> t; a = mint(t); return (is);
    }
    mint inv() const { return pow(mod - 2); }
    mint pow(ll n) const {
        mint ret(1), mul(x);
        while (n > 0) {
            if (n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }
};

struct SCC {
  vv<ll>& g;
  vv<ll> dag, rg;
  vl cmp, ord;
  vec<bool> use;
  vv<ll> blng;

  SCC(vv<ll>& g) : g(g), use(sz(g), 0) { build(); }

  ll operator[](ll k) { return cmp[k]; }

  vl& belong(ll i) { return blng[i]; }

  void dfs(ll p) {
    if (use[p]) return;
    use[p] = 1;
    for (auto e : g[p]) dfs(e);
    ord.push_back(p);
  }

  void rdfs(ll p, ll cnt) {
    if (cmp[p] != -1) return;
    cmp[p] = cnt;
    for (auto e : rg[p]) rdfs(e, cnt);
  }

  void build() {
    rep(i, sz(g)) { dfs(i); }
    reverse(all(ord));
    use.clear(), use.shrink_to_fit();
    cmp.resize(sz(g), -1ll), rg.resize(sz(g));
    rep(i, sz(g)) {
      for (auto e : g[i]) { rg[e].emplace_back(i); }
    }
    ll ptr = 0;
    for (ll i : ord)
      if (cmp[i] == -1) rdfs(i, ptr), ptr++;
    rg.clear(), rg.shrink_to_fit();
    ord.clear(), ord.shrink_to_fit();
    dag.resize(ptr), blng.resize(ptr);
    rep(i, sz(g)) {
      blng[cmp[i]].push_back(i);
      for (auto& to : g[i]) {
        ll x = cmp[i], y = cmp[to];
        if (x == y) continue;
        dag[x].push_back(y);
      }
    }
  }
};

void solve(){
    ll N, M, K; cin >> N >> M >> K;
    vv<ll> G(N);
    vec<pll> E(M);
    rep(i, M){
        ll u, v; cin >> u >> v; u--; v--;
        G[u].push_back(v);
        E[i] = {u, v};
    }
    SCC scc(G);
    ll X = sz(scc.dag);
    vl a(X-1, 0);
    rep(i, M){
        ll u = E[i][0], v = E[i][1];
        if(abs(scc.cmp[u]-scc.cmp[v]) == 1){
            a[min(scc.cmp[u], scc.cmp[v])]=1;
        }
    }
    if(a != vl(X-1, 1)){
        cout << "No" << endl;
        return;
    }
    vl check(N, -1);
    vl bin(X, 0);
    rep(i, N){
        if(check[i] == -1){
            check[i] = 0;
            queue<ll> Q; Q.push(i);
            while(!Q.empty()){
                ll p = Q.front(); Q.pop();
                for(ll nx : G[p]){
                    if(scc.cmp[nx] != scc.cmp[p]) continue;
                    if(check[nx] == -1){
                        check[nx] = 1 - check[p];
                        Q.push(p);
                    }
                    if(check[p] == check[nx]){
                        bin[scc.cmp[p]] = 1;
                    }
                }
            }
        }
    }
    if(bin == vl(X, 1)){
        cout << "Yes" << endl;
    }
    else cout << "No" << endl;
}

int main(){
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    int t = 1;
    // cin >> t;
    while(t--){
        solve();
    }
}