#include <bits/stdc++.h>
using namespace std;
#define v vector
#define ii pair<int,int>
#define fi first
#define se second
const int SIZ = 200;
v<v<int>> adj(100000);
int main(){
cin.tie(NULL);
ios_base::sync_with_stdio(false);
int N,M,Q;
cin>>N>>M>>Q;
for(int i=0; i<M; i++){
int s,e;
cin>>s>>e;
s--;
e--;
adj[e].push_back(s);
}
v<v<ii>> longest(N);
v<int> used(N,-1);
v<int> dists(N);
for(int i=0; i<N; i++){
for(int c:adj[i]){
for(auto it:longest[c]){
if(used[it.se]!=i) dists[it.se]=0;
used[it.se]=i;
dists[it.se] = max(dists[i], it.fi+1);
}
}
longest[i].push_back({0, i});
for(int c:adj[i]){
for(auto it:longest[c]){
if(used[it.se]==i){
used[it.se]=-1;
longest[i].push_back({dists[it.se], it.se});
}
}
}
sort(longest[i].rbegin(), longest[i].rend());
while(longest[i].size()>SIZ+1) longest[i].pop_back();
}
v<int> Y(N,-1);
for(int q=0; q<Q; q++){
int t,y;
cin>>t>>y;
t--;
for(int i=0; i<y; i++){
int c;
cin>>c;
c--;
Y[c] = q;
}
if(y<SIZ && false){
bool done=false;
for(ii it:longest[t]){
if(Y[it.se]!=q){
cout<<it.fi<<endl;
done=true;
break;
}
}
if(!done) cout<<-1<<endl;
}
else{
v<int> dp(N,0);
for(int i=t; i>=0; i--){
for(int c:adj[t]) dp[c] = max(dp[c], dp[i]+1);
}
int out=-1;
for(int i=0; i<=t; i++) if(Y[i]!=q) out = max(out, dp[i]);
cout<<out<<endl;
}
}
}
