#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
const int N = 1e5;
const int SZ = 400;
vector<int> g[N+5], gg[N+5];
vector<pair<int,int> > calc[N+1];
signed main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, m, q; cin >> n >> m >> q;
for(int i = 0;i < m; i++){
int a, b; cin >> a >> b;
g[a].push_back(b);
gg[b].push_back(a);
}
vector<int> reach, dist(n+1), last(n+1, 0);
for(int i = 1;i <= n; i++){
reach.push_back(i);
for(auto to : gg[i]){
for(auto [d, u] : calc[to]){
if(last[u] == i){
dist[u] = max(dist[u], d + 1);
}else{
dist[u] = d + 1;
last[u] = i;
reach.push_back(u);
}
}
}
sort(all(reach),[&](int a, int b){
return dist[a] > dist[b];
});
for(int j = 0;j < min(SZ, (int)reach.size()); j++){
calc[i].push_back({dist[reach[j]], reach[j]});
}
reach.clear();
}
int timer = 1;
vector<int> del(n+1, 0);
while(q--){
int v, k; cin >> v >> k;
for(int i = 0;i < k; i++){
int x; cin >> x;
del[x] = timer;
}
if(k < SZ){
int ans = -1;
for(auto [d, u] : calc[v]){
if(del[u] != timer){
ans = d;
break;
}
}
cout << ans << '\n';
}else{
vector<int> d(n+1, -1);
for(int i = 1;i <= n; i++){
if(del[i] != timer){
d[i] = max(d[i], 0);
}
for(int to : g[i]){
if(d[i] != -1)
d[to] = max(d[to], d[i] + 1);
}
}
cout << d[v] << '\n';
}
timer++;
}
return 0;
}
