#include <bits/stdc++.h>
using namespace std;
const int lim = 10000000;
const int rad = 400;
int N;
vector<vector<int>> adj;
vector<vector<pair<int, int>>> dp;
void crea(int a) {
priority_queue<pair<int, int>> pq;
unordered_set<int> pr;
for (int x : adj[a]) {
pq.push({1, x});
for (auto j : dp[x]) pq.push({j.first+1, j.second});
}
int h = 0;
while (h < rad && !pq.empty()) {
auto aus = pq.top(); pq.pop();
if (pr.count(aus.second)) continue;
dp[a].push_back(aus);
pr.insert(aus.second);
h++;
}
}
int bfs(int a, unordered_set<int> skip) {
queue<int> n;
vector<int> dist(N);
dp.resize(N);
fill(dist.begin(), dist.end(), lim);
dist[a] = 0; n.push(a);
int m = -1;
while (!n.empty()) {
a = n.front(); n.pop();
if (!skip.count(a)) m = max(m, dist[a]);
for (int x : adj[a]) {
if (dist[x] < lim) continue;
dist[x] = dist[a]+1;
n.push(x);
}
}
return m;
}
int prec(int a, unordered_set<int> s) {
int m = -1;
if (!s.count(a)) m = 0;
for (int i = 0; i < dp[a].size(); i++) {
if (s.count(dp[a][i].second)) continue;
m = max(m, dp[a][i].first);
}
return m;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL); cout.tie(NULL);
int M, Q; cin >> N >> M >> Q;
adj.resize(N+1);
for (int i = 0; i < M; i++) {
int s, t; cin >> s >> t;
adj[t].push_back(s);
}
dp.resize(N+1);
for (int i = 1; i <= N; i++) crea(i);
for (int i = 0; i < Q; i++) {
int a; cin >> a >> M;
unordered_set<int> s;
for (int j = 0; j < M; j++) {
int aus; cin >> aus; s.insert(aus);
}
if (M > rad) cout << bfs(a, s) << "\n";
else cout << prec(a, s) << "\n";
}
}
