#include <bits/stdc++.h> using namespace std; #define int long long #define endl '\n' const int N = 100000 + 5; const int K = 300; int n, m, q, indeg[N]; vector<int> adj[N]; pair<int,int> L[N][K]; int sz[N]; pair<int,int> tmp[2*K]; void merge_lists(int u, int v) { int k = 0; for(int i = 0; i < sz[u]; i++) tmp[k++] = {L[u][i].first + 1, L[u][i].second}; for(int i = 0; i < sz[v]; i++) tmp[k++] = {L[v][i].first, L[v][i].second}; sort(tmp, tmp + k, [](pair<int,int> &a, pair<int,int> &b){ return a.second < b.second; }); int idx = 0; for(int i = 0; i < k; ) { int src = tmp[i].second, best = tmp[i].first, j = i+1; while(j < k && tmp[j].second == src){ best = max(best,tmp[j].first); j++; } L[v][idx++] = {best, src}; i = j; if(idx == K) break; } sz[v] = idx; sort(L[v], L[v] + sz[v], greater<pair<int,int>>()); } void init() { int IN[N]; for(int i = 1; i <= n; i++) IN[i] = indeg[i]; queue<int> q; for(int i = 1; i <= n; i++){ L[i][0] = {0, i}; sz[i] = 1; if(IN[i] == 0) q.push(i); } while(!q.empty()){ int u = q.front(); q.pop(); for(int v: adj[u]){ merge_lists(u,v); if(--IN[v]==0) q.push(v); } } } signed main() { ios::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr); cin >> n >> m >> q; for(int i = 1; i <= m; i++){ int u,v; cin >> u >> v; indeg[v]++; adj[u].push_back(v); } init(); while(q--){ int T,Y; cin>>T>>Y; int C[Y]; unordered_set<int> bad; bad.reserve(Y*2); for(int i=0;i<Y;i++){ cin>>C[i]; bad.insert(C[i]); } if(Y <= K){ bool found=0; for(int i=0;i<sz[T];i++){ if(!bad.count(L[T][i].second)){ cout<<L[T][i].first<<endl; found=1; break; } } if(!found) cout<<-1<<endl; } else{ queue<int> qq; int IN2[N], ans[N]; for(int i=1;i<=n;i++){ IN2[i]=indeg[i]; ans[i]=0; } for(int x:bad) ans[x]=-1e18; for(int i=1;i<=n;i++) if(IN2[i]==0) qq.push(i); while(!qq.empty()){ int u=qq.front(); qq.pop(); for(int v:adj[u]){ ans[v]=max(ans[v],ans[u]+1); if(--IN2[v]==0) qq.push(v); } } if(ans[T]<0) cout<<-1<<endl; else cout<<ans[T]<<endl; } } return 0; }