#include <bits/stdc++.h>
using namespace std;
using pint = pair<int, int>;
int n, m, q, seen[100001], dist[100001];
vector<int> adj[100001], freq[100001];
vector<pint> dp[100001];
int dfs(int i) {
if (seen[i] == -q) return dist[i];
dist[i] = seen[i] == q ? -n : 0;
seen[i] = -q;
for (int j: adj[i]) dist[i] = max(dist[i], dfs(j) + 1);
return dist[i];
}
int main() {
cin >> n >> m >> q;
while (m--) {
int s, e;
cin >> s >> e;
adj[e].emplace_back(s);
}
for (int i = 1; i <= n; ++i) {
int mx = 0;
for (int j: adj[i]) {
for (auto [d, k]: dp[j]) {
mx = max(mx, ++d);
freq[d].clear();
if (seen[k] == i) dist[k] = max(dist[k], d);
else {
seen[k] = i;
dist[k] = d;
}
}
}
for (int j: adj[i]) {
for (auto [d, k]: dp[j]) {
if (not seen[k]) continue;
freq[dist[k]].emplace_back(k);
seen[k] = 0;
}
}
for (freq[0] = {i}; ~mx; --mx) {
for (int j: freq[mx]) {
dp[i].emplace_back(mx, j);
if (dp[i].size() * dp[i].size() >= n) goto end;
}
}
end:;
}
for (; q; --q) {
int t, y;
cin >> t >> y;
for (int i = y; i--;) {
int c;
cin >> c;
seen[c] = q;
}
if (y < dp[t].size()) {
for (auto [d, j]: dp[t]) {
if (seen[j] == q) continue;
cout << d << endl;
break;
}
} else {
int ans = dfs(t);
cout << (ans < 0 ? -1 : ans) << endl;
}
}
}
