#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 1, Y = 100;
int dp[N];
vector<int> adj[N];
vector<pair<int, int>> best[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m, q;
cin >> n >> m >> q;
while (m--) {
int s, e;
cin >> s >> e;
adj[e].push_back(s);
}
for (int i = 1; i <= n; i++) {
map<int, int> len = {{i, 0}};
for (int j : adj[i])
for (auto &[l, k] : best[j])
len[k] = max(len[k], l + 1);
best[i].reserve(len.size());
for (auto &[j, l] : len)
best[i].emplace_back(l, j);
int size = min(Y, (int)len.size());
nth_element(best[i].begin(), best[i].begin() + size - 1, best[i].end(),
greater());
best[i].erase(best[i].begin() + size, best[i].end());
sort(best[i].begin(), best[i].end(), greater());
}
while (q--) {
int t, y;
cin >> t >> y;
int ans = -1;
if (y <= Y) {
set<int> busy;
while (y--) {
int c;
cin >> c;
busy.insert(c);
}
for (auto &[l, i] : best[t]) {
if (!busy.count(i)) {
ans = l;
break;
}
}
} else {
memset(dp, 0, sizeof(dp));
while (y--) {
int c;
cin >> c;
dp[c] = -1;
}
for (int i = 1; i <= t; i++)
if (dp[i] != -1)
for (int j : adj[i])
dp[i] = max(dp[i], dp[j] + 1);
ans = dp[t];
}
cout << ans << '\n';
}
}
