#include <bits/stdc++.h>
using namespace std;
#define finish(x) return cout << x << endl, 0
#define ll long long
const int N = 100001;
const int K = 300;
const int INF = (int)1e9;
int n, m, q, vis1[N], vis2[N];
vector <int> g[N];
vector <pair <int, int> > f[N];
int curt;
vector <pair <int, int> > merge(vector <pair <int, int> > &l, vector <pair <int, int> > &r){
curt++;
vector <pair <int, int> > ret;
int lpos = 0, rpos = 0;
int lsz = l.size(), rsz = r.size();
while(ret.size() < K && (lpos < lsz || rpos < rsz)){
pair <int, int> winner;
if(lpos == lsz){
winner = make_pair(r[rpos].first + 1, r[rpos].second);
rpos++;
}
else if(rpos == rsz){
winner = l[lpos];
lpos++;
}
else if(l[lpos].first > r[rpos].first + 1){
winner = l[lpos];
lpos++;
}
else{
winner = make_pair(r[rpos].first + 1, r[rpos].second);
rpos++;
}
if(vis2[winner.second] == curt) continue;
vis2[winner.second] = curt;
ret.push_back(winner);
}
return ret;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m >> q;
for(int i = 0 ; i < m ; i++){
int x, y;
cin >> x >> y;
x--; y--;
g[y].push_back(x);
}
for(int i = 0 ; i < n ; i++){
f[i].push_back(make_pair(0, i));
for(auto &j : g[i]){
f[i] = merge(f[i], f[j]);
}
}
for(int i = 1 ; i <= q ; i++){
int t, sz;
cin >> t >> sz;
t--;
for(int j = 0 ; j < sz ; j++){
int x;
cin >> x;
x--;
vis1[x] = i;
}
if(sz < K){
int ans = -1;
for(auto &j : f[t]){
if(vis1[j.second] == i) continue;
ans = j.first;
break;
}
cout << ans << "\n";
}
else{
vector <int> dist(t + 1, -INF);
dist[t] = 0;
int ans = -1;
for(int j = t ; j >= 0 ; j--){
for(auto &k : g[j]){
dist[k] = max(dist[k], 1 + dist[j]);
}
if(vis1[j] != i) ans = max(ans, dist[j]);
}
cout << ans << "\n";
}
}
}
