#include <bits/stdc++.h> using namespace std; const int MAX_N = 100000 + 10; const int SQ = 320; int n, m, q; vector<int> adj[MAX_N]; vector<pair<int, int>> fars[MAX_N]; bool block[MAX_N]; int main() { cin >> n >> m >> q; for (int i = 1, s, t; i <= m; ++i) { cin >> s >> t; adj[t].push_back(s); } for (int i = 1; i <= m; ++i) { fars[i].push_back({0, i}); for (int j : adj[i]) { vector<pair<int, int>> new_fars; for (int pi = 0, pj = 0; new_fars.size() < min(SQ, int(fars[i].size() + fars[j].size()));) { if (pi < fars[i].size() && (pj == fars[j].size() || fars[i][pi].first >= fars[j][pj].first + 1)) { new_fars.push_back(fars[i][pi++]); } else { new_fars.push_back(fars[j][pj++]); ++new_fars.back().first; } } fars[i] = new_fars; } } while (q--) { int t, y; cin >> t >> y; vector<int> blocks; while (y--) { int c; cin >> c; block[c] = true; blocks.push_back(c); } int res = -1; if (y < SQ) { for (auto [d, u] : fars[t]) { if (!block[u]) { res = d; break; } } } else { int d[t + 1]; for (int i = 1; i <= t; ++i) { if (block[i]) { d[i] = -1; } else { d[i] = 0; for (int j : adj[i]) { d[i] = max(d[i], d[j] + 1); } } } res = d[t]; } cout << res << '\n'; for (int c : blocks) { block[c] = false; } } }