#include<bits/stdc++.h>
#define fi first
#define se second
using namespace std;
using ll = long long;
const int N = 1e5;
const int INF = 1e9;
int n,m,q;
vector<int> adj[N+5];
int d[N+5],qe[N+5],busy[N+5];
bool f[N+5],fbusy[N+5];
int head = 0, tail = 0;
int dlen[N+5],dp[N+5];
vector<pair<int,int>> largest[N+5];
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n >> m >> q;
for(int i = 1,x,y; i <= m ; ++i){
cin >> x >> y;
adj[y].push_back(x);
}
vector<pair<int,int>> tmp;
for(int i = 1 ; i <= n ; ++i){
tmp.clear();
for(int j : adj[i]){
d[i] = max(d[i],d[j] + 1);
for(pair<int,int> j1 : largest[j])
if(j1.se + 1 > dlen[j1.fi]){
tmp.push_back({j1.fi,j1.se + 1});
dlen[j1.fi] = j1.se + 1;
}
}
tmp.push_back({i,0});
for(pair<int,int> j : tmp) {
if(dlen[j.fi] == j.se) {
largest[i].push_back(j);
dlen[j.fi] = 0;
}
}
sort(largest[i].begin(),largest[i].end(),[&](pair<int,int> x, pair<int,int>y){
return x.se > y.se;
});
while(largest[i].size() > 100) largest[i].pop_back();
}
for(int i = 1 ; i <= q ; ++i){ int t,k;
cin >> t >> k;
for(int j = 1 ; j <= k ; ++j) cin >> busy[j], fbusy[busy[j]] = 1;
if(k < 100){
for(pair<int,int> j : largest[t]) if(!fbusy[j.fi]){
// cout << j.fi << ',' << j.se << '\n';
cout << j.se << '\n';
break;
}
}
else{
for(int j = 1 ; j <= t ; ++j){
if(fbusy[j]) dp[j] = -INF;
else dp[j] = 0;
for(int j1 : adj[j]) dp[j] = max(dp[j],dp[j1]+1);
}
cout << max(dp[t],-1) << '\n';
}
for(int j = 1 ; j <= k ; ++j) fbusy[busy[j]] = 0;
}
return 0;
}
