#include<bits/stdc++.h>
using namespace std;
vector<pair<int,int>>bst[100100];
vector<int>adj[100100],radj[100100];
int towns;
bitset<100100>stuv;
int brute(int tw,vector<int>cant){
vector<int>mx(towns+1,0);
for(auto i:cant)
mx[i]=-1e9;
for(int i=1;i<towns;i++)
for(auto x:adj[i])
mx[x]=max(mx[x],mx[i]+1);
return max(-1,mx[tw]);
}
int dob(vector<int>cant,int tw){
int ans=-1;
for(auto i:cant)
stuv[i]=1;
for(auto [x,k]:bst[tw])
if(!stuv[k]){
ans=x;break;}
for(auto i:cant)
stuv[i]=0;
return ans;
}
map<int,int>whynot;
int main(){
cin.tie(0)->sync_with_stdio(0);
int n,m,q;
cin>>n>>m>>q;
for(int i=0;i<m;i++){
int a,b; cin>>a>>b;
adj[a].push_back(b);
radj[b].push_back(a);
}
towns=n;
for(int i=1;i<=n;i++){
whynot[i]=0;
for(auto k:radj[i])
for(auto[y,x]:bst[k])
whynot[x]=max(whynot[x],y+1);
for(auto[x,y]:whynot)
bst[i].push_back({y,x});
sort(bst[i].rbegin(),bst[i].rend());
while(bst[i].size()>200) bst[i].pop_back();
whynot.clear();
}
while(q--){
int twn,bus;
cin>>twn>>bus;
vector<int>v(bus);
for(auto&i:v)
cin>>i;
if(bus>=200)
cout<<brute(twn,v)<<'\n';
else cout<<dob(v,twn)<<'\n';
}
}
