#include "bits/stdc++.h"
using namespace std;
using ll = long long;
const int K = 300;
int usd[int(1e5) + 22];
vector<pair<int, int>> merge(const vector<pair<int, int>>& a, vector<pair<int, int>> b) {
for (auto& [x, y] : b) x++;
vector<pair<int, int>> res;
int i = 0, j = 0;
while (!(i == a.size() && j == b.size())) {
if (i == a.size()) {
res.push_back(b[j++]);
} else if (j == b.size()) {
res.push_back(a[i++]);
} else if (a[i].first > b[j].first) {
res.push_back(a[i++]);
} else {
res.push_back(b[j++]);
}
}
b.clear();
for (auto& [x, y] : res) {
if (!usd[y] && b.size() <= K) {
usd[y] = 1;
b.push_back({x, y});
}
}
for (auto& [x, y] : b) usd[y] = 0;
return b;
}
void solve () {
int n, m, q;
cin >> n >> m >> q;
vector<vector<int>> g(n);
for (int i = 0; i < m; i++) {
int x, y;
cin >> x >> y;
x--, y--;
g[y].push_back(x);
}
vector<vector<pair<int, int>>> dp(n);
for (int i = 0; i < n; i++) {
dp[i] = {{0, i}};
for (auto& j : g[i]) {
dp[i] = merge(dp[i], dp[j]);
}
}
while (q--) {
int v, cnt; cin >> v >> cnt; v--;
vector<int> V(cnt); for (auto& u : V) { cin >> u; u--; }
if (cnt <= K) {
int ans = -1;
for (auto& u : V) usd[u] = 1;
for (auto& [len, u] : dp[v]) {
if (!usd[u]) { ans = len; break; }
}
for (auto& u : V) usd[u] = 0;
cout << ans << '\n';
} else {
for (auto& u : V) usd[u] = 1;
vector<int> dp(n, -1);
for (int i = 0; i < n; i++) {
if (!usd[i]) dp[i] = 0;
for (auto& j : g[i]) if (dp[j] >= 0) dp[i] = max(dp[i], dp[j] + 1);
}
cout << dp[v] << '\n';
for (auto& u : V) usd[u] = 0;
}
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
