#include<bits/stdc++.h>
using namespace std;
#define debug(...) 40
 
using ll = long long;
using pii = pair<long long, long long>;
using db = long double;
// #define int long long
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FOD(i, a, b) for (int i = (a); i >= (b); i--)
#define REP(i, n) for (int i = 0; i < (n); i++)
template <class T1, class T2>bool chmax(T1 &a, T2 b){return a < b ? a = b, 1 : 0;}
template <class T1, class T2>bool chmin(T1 &a, T2 b){return a > b ? a = b, 1 : 0;}
const int maxn = 2e5 + 5;
const int mod = 998244353;
const ll inf = 1e18;
vector<int> ad[maxn];
vector<array<int, 2>> node[maxn];
int dis[maxn], vis[maxn], bad[maxn], dp[maxn];
void solve(){
  int n, m, q;
  cin >> n >> m >> q;
  REP(i, m){
    int u, v;
    cin >> u >> v;
    ad[v].pb(u);
  }
  const int block = 100;
  vector<int> cur;
  for (int i = 1; i <= n; i++, cur.clear()){
    for (auto j : ad[i]){
      for (auto [w, u] : node[j]){
        if (vis[u] == i) chmax(dis[u], w + 1);
        else vis[u] = i, dis[u] = w + 1, cur.pb(u);
      }
    }
    for (auto u : cur) node[i].pb({dis[u], u});
    node[i].pb({0, i});
    sort(node[i].rbegin(), node[i].rend());
    while(node[i].size() > block) node[i].pop_back();
  }
  FOR(cnt, 1, q){
    int t, k, x, ans = -1;
    cin >> t >> k;
    REP(i, k){
      int x;
      cin >> x;
      bad[x] = cnt;
    }
    if (k < block){
      for (auto [w, u] : node[t]){
        if (bad[u] != cnt){
          ans = w;
          break;
        }
      }
    }
    else{
      fill(dp, dp + n + 1, -1);
      for (int i = 1; i <= t; i++){
        if (bad[i] != cnt) dp[i] = 0;
        for (auto j : ad[i]){
          if (dp[j] != -1) chmax(dp[j], dp[i] + 1);
        }
      }
      ans = dp[t];
    }
    cout << ans << "\n";
  }
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tests = 1;
  // cin >> tests;
  for (int _ = 1; _ <= tests; _++){
    solve();
    cout << "\n";
  }
  return 0;
}
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... |