#include <bits/stdc++.h>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
using namespace std;
using pii = pair<int, int>;
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n, m, q;
cin >> n >> m >> q;
vector<vector<int> > graph(n+1);
vector<vector<pii> > best(n+1);
vector<int> vis(n+1, 0), dist(n+1, 0);
for(int i=0; i<m; i++) {
int a, b;
cin >> a >> b;
graph[b].push_back(a);
}
for(int u=1; u<=n; u++) {
vector<int> curr;
for(int &x : graph[u]) {
for(pii &next : best[x]) {
int v = next.second;
int w = next.first;
if(vis[v] == u) dist[v] = max(dist[v], w + 1);
else vis[v] = u, dist[v] = w + 1, curr.push_back(v);
}
}
best[u].push_back({ 0, u });
for(int &v : curr) best[u].push_back({ dist[v], v });
sort(rall(best[u]));
}
for(int tc=0; tc<q; tc++) {
int ep, c;
cin >> ep >> c;
vector<bool> bad(n+1, 0);
for(int i=0; i<c; i++) {
int x;
cin >> x;
bad[x] = 1;
}
int ans = -1;
if(c > 250 || q == 1) {
vector<int> dp(n+1, -1);
dp[ep] = 0;
for(int i=ep; i>=1; i--) {
if(dp[i] == -1) continue;
if(!bad[i]) ans = max(ans, dp[i]);
for(int &v : graph[i]) dp[v] = max(dp[v], dp[i] + 1);
}
} else {
int cnt = 0;
for(pii &v : best[ep]) {
if(bad[v.second] || cnt++ > 250) continue;
ans = v.first;
break;
}
}
cout << ans << '\n';
}
return 0;
}
