#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define ff first
#define ss second
#define pii pair<int, int>
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
int n, m, Q;
cin >> n >> m >> Q;
vector<int> E[n + 1];
while (m--) {
int x, y;
cin >> x >> y;
E[y].push_back(x);
}
int K = sqrt(1e5);
vector<bool> vis(n + 1);
vector<int> ind(n + 1);
vector<vector<pii>> v(n + 1);
for (int i = 1; i <= n; i++) {
priority_queue<pii> q;
for (auto j : E[i]) {
q.push({v[j][0].ff, j});
}
while (!q.empty() && sz(v[i]) < K) {
auto [d, x] = q.top(); q.pop();
int y = v[x][ind[x]].ss;
if (!vis[y]) {
vis[y] = true;
v[i].push_back({d + 1, y});
}
if (ind[x] + 1 < sz(v[x])) q.push({v[x][++ind[x]].ff, x});
}
for (auto j : E[i]) {
ind[j] = 0;
}
for (auto [d, j] : v[i]) {
vis[j] = false;
}
if (sz(v[i]) < K) v[i].push_back({0, i});
int lst = INT_MAX;
for (auto [d, j] : v[i]) {
assert(lst >= d);
lst = d;
}
}
while (Q--) {
int T, Y;
cin >> T >> Y;
vector<bool> vis(n + 1);
while (Y--) {
int x;
cin >> x;
vis[x] = true;
}
bool tr = false;
for (auto [d, j] : v[T]) {
if (!vis[j]) {
cout << d << '\n';
tr = true; break;
}
}
if (tr) continue;
vector<int> dp(n + 1, -1);
for (int i = 1; i <= n; i++) {
if (!vis[i]) dp[i] = 0;
for (auto j : E[i]) {
if (~dp[j]) dp[i] = max(dp[i], dp[j] + 1);
}
}
cout << dp[T] << '\n';
}
}
