#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#include <atcoder/scc>
int main(){
	int n,m,k;
	cin>>n>>m>>k;
	vector<int> u(m),v(m);
	for(int i=0;i<m;i++)cin>>u[i]>>v[i],u[i]--,v[i]--;
	atcoder::scc_graph graph(n);
	for(int i=0;i<m;i++)graph.add_edge(u[i],v[i]);
	auto vv=graph.scc();
	if(vv[0].size()==1){
		cout<<"No"<<endl;
		return 0;
	}
	vector<int> g(n);
	for(int i=0;i<vv.size();i++){
		for(int x:vv[i])g[x]=i;
	}
	if(g[0]!=0){
		cout<<"No"<<endl;
		return 0;
	}
	vector<vector<int>> sgraph(n);
	for(int i=0;i<m;i++){
		if(g[u[i]]==g[v[i]])sgraph[u[i]].push_back(v[i]);
	}
	vector<int> f(n,-1);
	for(int i=0;i<vv.size();i++){
		if(vv[i].size()==1)continue;
		f[vv[i][0]]=0;
		bool ok=false;
		queue<int> bfs;
		bfs.push(vv[i][0]);
		while(!bfs.empty()){
			int x=bfs.front();
			bfs.pop();
			for(int y:sgraph[x]){
				if(f[y]==-1){
					f[y]=1-f[x];
					bfs.push(y);
				}else{
					if(f[x]==f[y])ok=true;
				}
			}
		}
		if(!ok){
			cout<<"No"<<endl;
			return 0;
		}
	}
	vector<vector<int>> bgraph(vv.size());
	for(int i=0;i<m;i++){
		bgraph[g[u[i]]].push_back(g[v[i]]);
	}
	for(int i=0;i<vv.size()-1;i++){
		bool ok=false;
		for(int j:bgraph[i])if(j==i+1)ok=true;
		if((!ok)||(vv[i].size()==1&&vv[i+1].size()==1)){
			cout<<"No"<<endl;
			return 0;
		}
	}
	cout<<"Yes"<<endl;
}