#include <bits/stdc++.h>
using namespace std;
const int N = 100'000 + 10;
int n, m, q;
vector<int> ad[N], rAd[N];
int deg[N];
bool mk[N];
int f[N];
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m >> q;
for (int i = 1; i <= m; ++i) {
int u, v; cin >> u >> v;
ad[u].push_back(v);
rAd[v].push_back(u);
}
vector<int> order;
{ // toposort
for (int u = 1; u <= n; ++u) {
for (const auto& v : ad[u]) deg[v] += 1;
}
queue<int> q;
for (int i = 1; i <= n; ++i) if (!deg[i]) q.push(i);
while (q.size()) {
auto u = q.front(); q.pop();
order.push_back(u);
for (const auto& v : ad[u]) {
if (!--deg[v]) q.push(v);
}
}
}
reverse(order.begin(), order.end());
while (q--) {
int x, k; cin >> x >> k;
vector<int> vt(k);
for (auto& u : vt) cin >> u, mk[u] = true;
int answer = -1;
fill(f + 1, f + n + 1, -1'000'000);
f[x] = 0;
for (const auto& u : order) {
for (const auto& v : rAd[u]) f[v] = max(f[v], f[u] + 1);
if (!mk[u]) answer = max(answer, f[u]);
}
cout << answer << "\n";
for (const auto& u : vt) mk[u] = false;
}
}
