//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#define ll long long
#define maxn 100005
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
const int siz = 320;
vector<int> adj[maxn];
int dp[maxn];
bool part[maxn];
void getdp(int n) {
for (int i = 1;i <= n;i++) dp[i] = 0;
for (int i = 1;i <= n;i++) {
for (int v:adj[i]) {
dp[v] = max(dp[v], (dp[i] == 0 ? (part[i] ? -1 : 0) : dp[i]) + 1);
}
}
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(0);
int n, m, q;
cin >> n >> m >> q;
for (int i = 0;i < m;i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
}
getdp(n);
while (q--) {
int ind, yi;
cin >> ind >> yi;
vector<int> val;
for (int i = 0;i < yi;i++) {
int x;
cin >> x;
part[x] = 1;
val.push_back(x);
}
getdp(n);
if (part[ind] && dp[ind] == 0) cout << -1 << "\n";
else cout << dp[ind] << "\n";
for (int i:val) part[i] = 0;
}
}
/*
5 6 3
1 2
2 4
3 4
1 3
3 5
4 5
4 1 1
5 2 2 3
2 3 1 4 5
*/
