/**
	author:  shobonvip
	created: 2026.04.19 08:29:12
**/

#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)
#define all(v) v.begin(), v.end()

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

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

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int n, m; cin >> n >> m;
	int k; cin >> k;
	vector<pair<int,int>> edge;
	scc_graph scc(n);
	rep(i,0,m) {
		int u, v;
		cin >> u >> v;
		u--; v--;
		edge.emplace_back(u, v);
		scc.add_edge(u, v);
	}

	vector<vector<int>> g = scc.scc();
	vector<int> taio(n, -1);
	
	vector cango(n, vector<int>(0));
	vector inner(n, vector<int>(0));
	
	rep(i,0,(int)g.size()) {
		rep(j,0,(int)g[i].size()) {
			taio[g[i][j]] = i;
		}
	}

	rep(i,0,m) {
		auto [u,v] = edge[i];
		if (taio[u] == taio[v]) {
			inner[u].emplace_back(v);
			continue;
		}
		cango[taio[u]].emplace_back(taio[v]);
	}

	vector<int> d(n, -1);
	auto dfs = [&](auto self, int i) -> int {
		if (d[i] != -1) return d[i];
		int v = 1;
		for (int j: cango[i]) {
			chmax(v, self(self, j) + 1);
		}
		d[i] = v;
		return v;
	};
	dfs(dfs, taio[0]);

	if (d[taio[0]] != (int)g.size()) {
		cout << "No\n";
		return 0;
	}

	
	vector<int> road;
	auto dfs2 = [&](auto self, int i) -> void {
		road.emplace_back(i);
		for (int j: cango[i]) {
			if (d[i] - 1 == d[j]) {
				self(self, j);
				break;
			}
		}
	};

	dfs2(dfs2, taio[0]);

	rep(i,0,(int)road.size() - 1) {
		if (g[road[i]].size() == 1 && g[road[i+1]].size() == 1) {
			cout << "No\n";
			return 0;
		}
	}

	vector<int> tansaku(n, -1);
	int gs = 0;
	auto dfs3 = [&](auto self, int i) -> void {
		for (int j: inner[i]) {
			if (tansaku[j] == -1) {
				tansaku[j] = tansaku[i] + 1;
				self(self, j);
			} else {
				gs = gcd(gs, abs(tansaku[i] - tansaku[j] + 1));
			}
		}
	};


	rep(i,0,(int)road.size()) {
		gs = 0;
		tansaku[g[road[i]].front()] = 0;
		dfs3(dfs3, g[road[i]].front());
		if (gs > 0 && gs % 2 == 0) {
			cout << "No\n";
			return 0;
		} 
	}

	cout << "Yes\n";
	return 0;
	

	


}