#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define FAST_IO ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);cerr.tie(0)
#define pb push_back
#define all(x) begin(x), end(x)
#define umap unordered_map
#define space " "
#define TEST_CASES int a; cin >> a; for (int i = 0; i < a; i++) {solve(); cout << endl;}
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
void solve() {
int b, c, d; cin >> b >> c >> d;
int block = sqrt(1e5);
vector<vector<int>> adj(b + 1);
for (int i = 0; i < c; i++) {
int x, y; cin >> x >> y;
adj[y].pb(x);
}
vector<vector<pair<int, int>>> keeps(b + 1);
vector<bool> visited(b + 1);
for (int i = 1; i <= b; i++) {
priority_queue<pair<pair<int, int>, int>> pq;
for (int j = 0; j < adj[i].size(); j++) {
pq.push({{keeps[adj[i][j]][0].first, 0}, adj[i][j]});
}
for (int j = 0; j < block; j++) {
if (pq.empty()) {
break;
}
auto curr = pq.top(); pq.pop();
int dist = curr.first.first; int pos = curr.first.second; int node = curr.second;
if (!visited[keeps[node][pos].second]) {
keeps[i].pb({dist + 1, keeps[node][pos].second});
visited[keeps[node][pos].second] = true;
j--;
}
if (pos != keeps[node].size() - 1) {
pq.push({{keeps[node][pos + 1].first, pos + 1}, node});
}
}
for (auto x : keeps[i]) {
visited[x.second] = false;
}
if (keeps[i].size() != block) {
keeps[i].pb({0, i});
}
}
while (d--) {
int node; cin >> node;
int n; cin >> n;
vector<int> vec(n);
for (int i = 0; i < n; i++) {
cin >> vec[i];
visited[vec[i]] = true;
}
if (n >= block) {
vector<int> large(node + 1, -1);
for (int i = 1; i <= node; i++) {
if (!visited[i]) {
large[i] = max(large[i], 0);
}
for (int j = 0; j < adj[i].size(); j++) {
if (!visited[adj[i][j]]) {
large[i] = max(large[i], large[adj[i][j]] + 1);
}
}
}
cout << large[node] << endl;
}
else {
bool flag = false;
for (int i = 0; i < keeps[node].size(); i++) {
if (!visited[keeps[node][i].second]) {
cout << keeps[node][i].first << endl;
flag = true; break;
}
}
if (!flag) {
cout << -1 << endl;
}
}
for (int i = 0; i < n; i++) {
visited[vec[i]] = false;
}
}
}
int main() {
FAST_IO;
//freopen("cowmbat.in", "r", stdin);
//freopen("cowmbat.out", "w", stdout);
//TEST_CASES;
solve(); cout << endl;
/*int a; cin >> a;
for (int i = 1; i <= a; i++){
cout << "Case #" << i << ": ";
solve();
cout << endl;
}*/
}
