#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <unordered_map>
#include <set>
#include <cstring>
#define endl '\n'
using namespace std;
vector<int> v[600000];
bool ne[600000];
int dp[600000];
bool used[600000];
void dfs(int i) {
used[i]=1;
for(auto x : v[i]) {
dp[x]=max(dp[x], dp[i]+1);
dfs(x);
}
}
int main() {
ios::sync_with_stdio(false);
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;
v[b].push_back(a);
}
while(q--) {
int t,y; cin >> t >> y;
while(y--) {
int a; cin >> a;
ne[a]=1;
}
dp[t]=0;
dfs(t);
int ans=-1;
for(int i = 1; i <= n; i++) {
if(ne[i]) continue;
if(used[i]) ans=max(ans, dp[i]);
}
cout << ans << endl;
memset(ne, 0, sizeof(ne));
memset(used, 0, sizeof(used));
for(int i = 1; i <= n; i++) dp[i]=-1;
}
}
/*
5 6 1
1 2
2 4
3 4
1 3
3 5
4 5
5 2 2 3
*/
