#include <bits/stdc++.h>
using namespace std;
#define sz(v) (int)v.size()
const int MAXN = 1e5+5;
vector<int> radj[MAXN], ini[MAXN], dist[MAXN];
int mx[MAXN], marc[MAXN], val[MAXN];
bool cmp(int a, int b){
return mx[a] > mx[b];
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int B = 158;
int n,m,q; cin>>n>>m>>q;
for(int i = 1; i <= m; i++){
int a,b; cin>>a>>b;
radj[b].push_back(a);
}
for(int i = 1; i <= n; i++){
vector<int> v;
for(int k = 0; k < sz(radj[i]); k++){
for(int j = 0; j < sz(ini[radj[i][k]]); j++){
if(mx[ ini[radj[i][k]][j] ] == 0){
mx[ ini[radj[i][k]][j] ] = dist[radj[i][k]][j] + 1;
v.push_back( ini[radj[i][k]][j] );
}else{
mx[ ini[radj[i][k]][j] ] = max( mx[ ini[radj[i][k]][j] ], dist[radj[i][k]][j] + 1);
}
}
}
sort(v.begin(),v.end(),cmp);
for(int j = 0; j < sz(v); j++){
if(mx[v[j]] == 0)break;
if(j < B){ ini[i].push_back(v[j]); dist[i].push_back( mx[v[j]] ); }
mx[v[j]] = 0;
}
ini[i].push_back( i ); dist[i].push_back( 0 );
}
for(int id = 1; id <= q; id++){
int v, qtd; cin>>v>>qtd;
vector<int> block(qtd);
for(int i = 0; i < qtd; i++){
cin>>block[i];
marc[block[i]] = 1;
}
if(qtd >= B){
for(int i = 1; i <= n; i++){
val[i] = -1;
if(!marc[i])val[i] = 0;
for(int viz : radj[i])
if(val[viz] != -1)val[i] = max(val[i], val[viz]+1);
}
cout<<val[v]<<"\n";
}else{
int ok = 0;
for(int i = 0; i < sz(dist[v]); i++)
if(!marc[ ini[v][i] ]){ok = 1; cout<<dist[v][i]<<"\n"; break; }
if(!ok)cout<<"-1\n";
}
for(int i = 0; i < qtd; i++)marc[block[i]] = 0;
}
}
