#include<bits/stdc++.h> using namespace std; const int bs = 320; vector<int> ad[100005]; vector<pair<int, int>> option[100005]; bool used[100005]; void combine(vector<pair<int, int>> &a, vector<pair<int, int>> &b) { vector<pair<int, int>> ans; int j = 0; for(int i = 0; i < a.size(); i++) if(ans.size() < bs){ while(j < b.size() && b[j].first > a[i].first && ans.size() < bs){ if(used[b[j].second] == 0){ used[b[j].second] = 1; ans.push_back(b[j]); } j++; } if(ans.size() == bs) break; ans.push_back(a[i]); used[a[i].second] = 1; } while(j < b.size() && ans.size() < bs){ if(used[b[j].second] == 0){ used[b[j].second] = 1; ans.push_back(b[j]); } j++; } a = ans; for(pair<int, int> &i : ans) used[i.second] = 0; } int dp[100005]; int main() { ios_base::sync_with_stdio(false); cin.tie(0); int n, m, q; cin>>n>>m>>q; for(int i = 1; i <= m; i++){ int u, v; cin>>u>>v; ad[v].push_back(u); } //Now calculate sqrt(n) best option for(int i = 1; i <= n; i++){ for(int v : ad[i]) combine(option[i], option[v]); if(option[i].size() < bs) option[i].push_back({-1, i}); for(auto &j : option[i]) j.first++; //cerr<<"A"<<i<<endl; //for(auto j : option[i]) cerr<<j.first<<" "<<j.second<<endl; } for(int test = 0; test < q; test++){ int u, nn; cin>>u>>nn; if(nn >= bs){ //Brute solve memset(dp, 0, sizeof(dp)); for(int i = 1; i <= nn; i++){ int x; cin>>x; dp[x] = -1e9; } for(int i = 1; i <= u; i++) for(int v : ad[i]) dp[i] = max(dp[i], dp[v] + 1); cout<<max(dp[u], -1)<<'\n'; } else{ vector<int> a(nn); for(int i = 0; i < nn; i++) cin>>a[i]; for(int i : a) used[i] = 1; int ans = -1; for(auto &i : option[u]) if(used[i.second] == 0){ans = i.first; break;} for(int i : a) used[i] = 0; cout<<ans<<'\n'; } } }