#include<bits/stdc++.h> #define fi first #define se second using namespace std; using ll = long long; const int N = 1e5; const int INF = 1e9; int n,m,q; vector<int> adj[N+5]; int d[N+5],qe[N+5],busy[N+5]; bool f[N+5],fbusy[N+5]; int head = 0, tail = 0; int dlen[N+5],dp[N+5]; vector<pair<int,int>> largest[N+5]; int main(){ ios::sync_with_stdio(0);cin.tie(0);cout.tie(0); cin >> n >> m >> q; for(int i = 1,x,y; i <= m ; ++i){ cin >> x >> y; adj[y].push_back(x); } vector<pair<int,int>> tmp; for(int i = 1 ; i <= n ; ++i){ tmp.clear(); for(int j : adj[i]){ d[i] = max(d[i],d[j] + 1); for(pair<int,int> j1 : largest[j]) if(j1.se + 1 > dlen[j1.fi]){ tmp.push_back({j1.fi,j1.se + 1}); dlen[j1.fi] = j1.se + 1; } } tmp.push_back({i,0}); for(pair<int,int> j : tmp) { if(dlen[j.fi] == j.se) { largest[i].push_back(j); dlen[j.fi] = 0; } } sort(largest[i].begin(),largest[i].end(),[&](pair<int,int> x, pair<int,int>y){ return x.se > y.se; }); while(largest[i].size() > 100) largest[i].pop_back(); } for(int i = 1 ; i <= q ; ++i){ int t,k; cin >> t >> k; for(int j = 1 ; j <= k ; ++j) cin >> busy[j], fbusy[busy[j]] = 1; // cout << fbusy[2] << "!\n"; if(k < 100){ bool ok = false; for(pair<int,int> j : largest[t]) if(!fbusy[j.fi]){ // cout << j.fi << ',' << j.se << '.' << fbusy[j.fi] << '\n'; cout << j.se << '\n'; ok = true;break; } // cout << ok << "!!!\n"; if(!ok) cout << -1 << '\n'; } else{ for(int j = 1 ; j <= t ; ++j){ if(fbusy[j]) dp[j] = -INF; else dp[j] = 0; for(int j1 : adj[j]) dp[j] = max(dp[j],dp[j1]+1); } cout << max(dp[t],-1) << '\n'; } for(int j = 1 ; j <= k ; ++j) fbusy[busy[j]] = 0; } return 0; }