#include <bits/stdc++.h>
using namespace std;
int N, M, Q;
vector<vector<int>> adj, revAdj;
vector<int> memo;
int goal;
int dp(int pos) {
if (pos > goal) return INT_MIN;
if (pos == goal) return 0;
if (memo[pos] != -1) return memo[pos];
int ans = INT_MIN;
for (int x : adj[pos]) {
ans = max(ans, dp(x) + 1);
}
return memo[pos] = ans;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
cin >> N >> M >> Q;
adj.resize(N); revAdj.resize(N);
for (int i = 0; i < M; i++) {
int a, b; cin >> a >> b; a--; b--;
adj[a].push_back(b);
revAdj[b].push_back(a);
}
vector<vector<int>> busy(Q);
vector<bool> dec(Q, false);
vector<int> T(Q);
for (int i = 0; i < Q; i++) {
cin >> T[i]; T[i]--;
int Y; cin >> Y;
for (int j = 0; j < Y; j++) {
int a; cin >> a; a--;
busy[i].push_back(a);
}
if (Y < sqrt(N) - 230) dec[i] = true;
}
vector<set<pair<int,int>>> sol(N);
for (int i = 0; i < N; i++) {
sol[i].insert({0,i});
vector<set<pair<int,int>>::iterator> it(int(revAdj[i].size()));
for (int k = 0; k < int(revAdj[i].size()); k++) it[k] = sol[revAdj[i][k]].begin();
for (int k = 0; k < sqrt(N) - 230; k++) {
pair<int,int> best = {INT_MAX, -1};
int index = -1;
for (int j = 0; j < int(revAdj[i].size()); j++) {
if (it[j] != sol[revAdj[i][j]].end() && *it[j] < best) {
best = *it[j];
best.first--;
index = j;
}
}
if (index != -1) {
it[index]++;
sol[i].insert(best);
}
}
}
for (int i = 0; i < Q; i++) {
if (!dec[i]) {
goal = T[i];
memo.clear(); memo.resize(T[i], -1);
int ans = -1;
for (int j = 0; j <= goal; j++) {
auto it = lower_bound(busy[i].begin(), busy[i].end(), j);
if (it == busy[i].end() || (*it) != j) ans = max(ans, dp(j));
}
cout << ans << '\n';
}
else {
bool ok = false;
for (auto x : sol[T[i]]) {
auto it = lower_bound(busy[i].begin(), busy[i].end(), x.second);
if (it == busy[i].end() || (*it) != x.second) {
ok = true;
cout << -x.first << '\n';
break;
}
}
if (!ok) cout << -1 << '\n';
}
}
return 0;
}
