#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 100'005, B = 10;
vector<int> adj[N];
vector<array<int, 2>> dp[N];
int dp2[N];
bool bad[N];
void dfs(int i) {
if (dp[i].size()) return;
for (auto nxt : adj[i]) {
dfs(nxt);
int sz = dp[i].size();
for (auto j : dp[nxt]) {
dp[i].push_back(j);
}
inplace_merge(dp[i].begin(), dp[i].begin() + sz, dp[i].end());
while (dp[i].size() > B) dp[i].pop_back();
}
for (auto &[x, idx] : dp[i]) {
x--;
}
dp[i].push_back({0, i});
inplace_merge(dp[i].begin(), dp[i].begin() + dp[i].size() - 1, dp[i].end());
if (dp[i].size() > B) dp[i].pop_back();
}
int dfs2(int i) {
if (~dp2[i]) return dp2[i];
int mx = 0;
if (bad[i]) mx = -1e9;
for (auto nxt : adj[i]) {
mx = max(mx, dfs2(nxt) + 1);
}
return dp2[i] = mx;
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int n, m, q;
cin >> n >> m >> q;
for (int i = 0, u, v; i < m; i++) {
cin >> u >> v;
adj[v].push_back(u);
}
for (int i = 1; i <= n; i++) {
dfs(i);
}
while (q--) {
int t, y;
cin >> t >> y;
int c[y];
for (int i = 0; i < y; i++) {
cin >> c[i];
bad[c[i]] = 1;
}
if (y >= B) {
for (int i = 1; i <= n; i++) {
dp2[i] = -1;
}
cout << max(-1, dfs2(t)) << '\n';
} else {
int ans = -1;
for (auto [x, i] : dp[t]) {
if (bad[i]) continue;
ans = -x;
break;
}
cout << ans << '\n';
}
for (int i = 0; i < y; i++) {
bad[c[i]] = 0;
}
}
return 0;
}
