#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pll pair<int, int>
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define endl '\n'
const int blk=300;
int n,m,q;
vector<vector<pll>> best(100005);
vector<vector<int>> fro(100005);
vector<bool> exist(100005, 1);
vector<int> mem(100005, -2);
int slow(int x){
if(mem[x]!=-2)return mem[x];
if(exist[x])mem[x]=0;
else mem[x]=-1;
for(auto it:fro[x]){
int ret=slow(it);
//~ printf("at x %lld, from it %lld, ret is %lld\n", x, it, ret);
if(ret != -1)mem[x]=max(mem[x], ret+1);
}
return mem[x];
}
signed main(){
cin>>n>>m>>q;
for(int i=0;i<m;i++){
int a,b;cin>>a>>b;
assert(a<b);
fro[b].pb(a);
}
//~ for(int i=1;i<=n;i++){
//~ best[i][0]={0, i};
//~ }
//~ for(int i=1;i<=n;i++){
//~ // calculate best (max distance to) 300 nodes.
//~ map<int,int> m;
//~ m[i]=0;
//~ for(auto it:fro[i]){
//~ for(auto [node,dist] : best[it]){
//~ m[node]=max(m[node], dist+1);
//~ }
//~ }
//~ int cnt=0;
//~ for(auto [node, dist]:m){
//~ if(cnt >= blk) break;
// printf("i %lld, node %lld, dist %lld\n", i, node, dist);
//~ best[i].pb({node, dist});
//~ cnt++;
//~ }
//~ }
while(q--){
int t,y;cin>>t>>y;
vector<int> blocked;
for(int i=0;i<y;i++){
int c;cin>>c;
exist[c]=0;
blocked.pb(c);
}
//~ if(y<blk){
//~ // go thru best[t]
//~ for(int i=0;i<(int)best[t].size();i++){
//~ auto [node, dist]=best[t][i];
//~ if(exist[node]){
//~ // //~ printf("%lld best of t %lld is %lld and it exists\n", i,t,best[t][i].s);
//~ cout<<dist<<"\n";
//~ break;
//~ }
//~ if(i==(int)best[t].size()-1){
//~ cout<<-1<<"\n";
//~ }
//~ }
//~ }
//~ else {
fill(mem.begin(),mem.end(),-2);
cout<<slow(t)<<"\n";
//~ }
//~ for(int i=1;i<=n;i++){
//~ cout<<mem[i]<<" ";
//~ }
//~ cout<<endl;
for(auto it:blocked){
exist[it]=1;
}
}
}
