#include <bits/stdc++.h>
using namespace std;
int N, M, Q;
vector<vector<int>> adj;
vector<bool> busy;
vector<int> memo;
int target;
const int NEG_INF = -1000000000;
int dfs(int u) {
if (busy[u]) return NEG_INF;
int &res = memo[u];
if (res != INT_MIN) return res;
if (u == target) return res = 0;
int best = NEG_INF;
for (int v : adj[u]) {
int d = dfs(v);
if (d > NEG_INF) best = max(best, d + 1);
}
return res = best;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> N >> M >> Q;
adj.assign(N + 1, {});
for (int i = 0; i < M; i++) {
int S, E;
cin >> S >> E;
adj[S].push_back(E);
}
busy.resize(N + 1);
memo.resize(N + 1);
while (Q--) {
cin >> target;
int Y;
cin >> Y;
fill(busy.begin(), busy.end(), false);
for (int i = 0; i < Y; i++) {
int x;
cin >> x;
busy[x] = true;
}
for (int i = 1; i <= N; i++) memo[i] = INT_MIN;
int ans = NEG_INF;
for (int i = 1; i <= N; i++) {
if (i == target || !busy[i]) {
ans = max(ans, dfs(i));
}
}
if (ans < 0) cout << -1 << '\n';
else cout << ans << '\n';
}
return 0;
}
