#include<iostream>
#include<vector>
using namespace std;
typedef pair<int,int> pii;
int N, M, K;
vector<pii> must;
vector<pii> no;
int main() {
cin>>N>>M>>K;
for(int i=0; i<M; i++) {
int a, b;
cin>>a>>b;
must.push_back({a, b});
}
for(int i=0; i<K; i++) {
int a, b;
cin>>a>>b;
no.push_back({a, b});
}
int a = no[0].first, b = no[0].second, c = no[1].first, d = no[1].second;
if(a==d && b==c) {cout<<"NO"; return 0;}
if(a==c) {
cout<<d<<' '<<c<<'\n'<<b<<' '<<a<<'\n';
int pre = a;
for(int i=0; i<N; i++) {
if(i == a || i == b || i == c || i == d) continue;
cout<<pre<<' '<<i<<'\n';
pre = i;
}
}
else if(b == d) {
cout<<d<<' '<<c<<'\n'<<b<<' '<<a<<'\n';
int pre = a;
for(int i=0; i<N; i++) {
if(i == a || i == b || i == c || i == d) continue;
cout<<pre<<' '<<i<<'\n';
pre = i;
}
}
else if(a == d) {
cout<<d<<' '<<c<<'\n'<<b<<' '<<a<<'\n';
int pre = c;
for(int i=0; i<N; i++) {
if(i == a || i == b || i == c || i == d) continue;
cout<<pre<<' '<<i<<'\n';
pre = i;
}
}
else if(b == c) {
cout<<d<<' '<<c<<'\n'<<b<<' '<<a<<'\n';
int pre = a;
for(int i=0; i<N; i++) {
if(i == a || i == b || i == c || i == d) continue;
cout<<pre<<' '<<i<<'\n';
pre = i;
}
}
}
