#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 1e5 + 10;
const int INF = 1e9;
vector<int> g[N];
int n, m, q;
vector<int> order;
bool us[N];
void topsort(int v) {
us[v] = 1;
for(int to : g[v]) {
if(us[to]) continue;
topsort(to);
}
order.push_back(v);
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin >> n >> m >> q;
for(int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
g[u].push_back(v);
}
for(int i = 1; i <= n; i++) {
if(us[i]) continue;
topsort(i);
}
while(q--) {
int t, y;
cin >> t >> y;
set<int> st;
for(int i = 0; i < y; i++) {
int v;
cin >> v;
st.insert(v);
}
vector<int> dp(n + 1, -2 * INF);
dp[t] = 0;
for(int cur : order) {
for(int to : g[cur]) dp[cur] = max(dp[cur], dp[to] + 1);
}
int ans = -INF;
for(int i = 1; i <= n; i++) {
if(st.count(i)) continue;
ans = max(ans, dp[i]);
}
if(ans == -INF) ans = -1;
cout << ans << '\n';
}
}
