#include <bits/stdc++.h> using namespace std; using pii = pair<int,int>; int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); int N,M,Q; if(!(cin>>N>>M>>Q)) return 0; int k = (int)sqrt(N) + 1; vector<vector<int>> add(N+1), rem(N+1); for(int i=0;i<M;i++){ int s,e; cin>>s>>e; add[s].push_back(e); rem[e].push_back(s); } vector<vector<pii>> st(N+1); vector<int> seen(N+1, 0), best(N+1, 0); for(int v=1; v<=N; ++v){ vector<int> list_srcs; list_srcs.reserve( max(1, (int)rem[v].size()*min(k,5)) ); for(int u : rem[v]){ auto &su = st[u]; for(auto &p : su){ int src = p.second; int val = p.first + 1; if(seen[src] != v){ seen[src] = v; best[src] = val; list_srcs.push_back(src); } else if(best[src] < val){ best[src] = val; } } if(seen[u] != v){ seen[u] = v; best[u] = 1; list_srcs.push_back(u); } else if(best[u] < 1){ best[u] = 1; } } if(seen[v] != v){ seen[v] = v; best[v] = 0; list_srcs.push_back(v); } else if(best[v] < 0){ best[v] = 0; } vector<pii> items; items.reserve(list_srcs.size()); for(int src : list_srcs) items.emplace_back(best[src], src); if((int)items.size() > k){ auto cmp = [](const pii &a, const pii &b){ return a.first > b.first; }; nth_element(items.begin(), items.begin()+k, items.end(), cmp); items.resize(k); sort(items.begin(), items.end(), cmp); } else { sort(items.begin(), items.end(), [](const pii &a, const pii &b){ return a.first > b.first; }); } st[v].swap(items); } vector<int> dp(N+1, -1000000000); while(Q--){ int T, Y; cin >> T >> Y; vector<int> busy(Y); for(int i=0;i<Y;i++) cin>>busy[i]; if(Y < k){ unordered_set<int> busyset; busyset.reserve(Y*2+1); for(int b : busy) busyset.insert(b); int ans = -1000000000; for(auto &p : st[T]){ if(busyset.find(p.second) == busyset.end()){ ans = max(ans, p.first); break; } } if(ans == -1000000000) cout << -1 << '\n'; else cout << ans << '\n'; } else { for(int i=1;i<=N;i++) dp[i] = -1000000000; dp[T] = 0; for(int x=T; x>=1; --x){ if(dp[x] == -1000000000) continue; for(int u : rem[x]){ } for(int v : add[x]){ if(dp[v] != -1000000000){ } } int bestx = dp[x]; for(int v: add[x]){ if(dp[v] != -1000000000) bestx = max(bestx, dp[v] + 1); } dp[x] = bestx; } vector<char> isbusy(T+1, 0); for(int b: busy) if(b<=T) isbusy[b]=1; int ans = -1000000000; for(int i=1;i<=T;i++){ if(!isbusy[i]) ans = max(ans, dp[i]); } if(ans == -1000000000) cout << -1 << '\n'; else cout << ans << '\n'; } } return 0; }