#include "bits/stdc++.h"
using namespace std;
using ll = long long;
const int SQRT = 350;
const int maxN = 1e5;
int dp[maxN + 5];
vector<int> adj[maxN + 5];
vector<pair<int, int>> root[maxN + 5];
int n, m, q;
void build() {
vector<int> seen(n + 5, 0);
vector<int> cost(n + 5, 0);
for (int i = 1; i <= n; i++) {
vector<int> r;
for (auto a : adj[i]) {
for (auto b : root[a]) {
if (seen[b.first] == i) {
cost[b.first] = max(cost[b.first], b.second + 1);
} else {
seen[b.first] = i;
cost[b.first] = b.second + 1;
r.push_back(b.first);
}
}
if (seen[a] != i) {
r.push_back(a);
cost[a] = 1;
seen[a] = i;
}
}
r.push_back(i);
sort(r.begin(), r.end(), [&](int a, int b) {
return cost[a] > cost[b];
});
int sz = min(SQRT, (int) r.size());
for (int j = 0; j < sz; j++) {
root[i].emplace_back(r[j], cost[r[j]]);
}
}
}
int main() {
cin >> n >> m >> q;
for (int i = 0; i < m; i++) {
int a, b; cin >> a >> b;
adj[b].push_back(a);
}
build();
vector<int> queries(n + 5);
for (int i = 1; i <= q; i++) {
int t, y; cin >> t >> y;
for (int j = 1; j <= y; j++) {
int x; cin >> x;
queries[x] = i;
}
if (y < SQRT) {
bool printed = false;
for(auto a : root[t]) {
if (queries[a.first] == i) continue;
cout << a.second << "\n";
printed = true;
break;
}
if (!printed) cout << -1 << "\n";
} else {
for (int j = 1; j <= n; j++) {
if (queries[j] != i) dp[j] = 0;
else dp[j] = -1;
for (auto k : adj[j]) {
if (dp[k] >= 0) dp[j] = max(dp[j], dp[k] + 1);
}
}
cout << dp[t] << "\n";
}
}
}
