#include <bits/stdc++.h>
using namespace std;
const int SIZE = 1;
int main(){
cin.sync_with_stdio(0); cin.tie(0);
int n, m, q;
cin >> n >> m >> q;
vector<int> edges[n];
for(int i = 0; i < m; i++){
int s, e;
cin >> s >> e;
s--; e--;
edges[e].push_back(s);
}
vector<pair<int,int> > best[n];
vector<int> seen(n, 0);
for(int b = 0; b < n; b++){
vector<pair<int,int> > cand;
cand.push_back({0,b});
for(int a : edges[b]){
for(pair<int,int> x : best[a]){
cand.push_back({x.first + 1, x.second});
}
}
sort(cand.begin(), cand.end());
reverse(cand.begin(), cand.end());
for(pair<int,int> x : cand){
if(seen[x.second]) continue;
if(best[b].size() > SIZE) break;
seen[x.second] = 1;
best[b].push_back(x);
}
for(pair<int,int> x : cand){
seen[x.second] = 0;
}
}
vector<int> attend(n, 1);
vector<int> dp(n, -1);
for(int qq = 0; qq < q; qq++){
int town, y;
cin >> town >> y;
town--;
vector<int> bad(y);
for(int i = 0; i < y; i++){
cin >> bad[i];
bad[i]--;
attend[bad[i]] = 0;
}
if(y < SIZE){
int ans = -1;
for(pair<int,int> x : best[town]){
if(attend[x.second]){
ans = x.first;
break;
}
}
cout << ans << '\n';
} else {
for(int b = 0; b < n; b++){
dp[b] = -1;
}
for(int b = 0; b < n; b++){
if(attend[b]){
dp[b] = 0;
}
for(int a : edges[b]){
if(dp[a] >= 0){
dp[b] = max(dp[b], dp[a] + 1);
}
}
}
cout << dp[town] << '\n';
}
for(int i = 0; i < y; i++){
attend[bad[i]] = 1;
}
}
}
