#include<bits/stdc++.h>
#define fi first
#define se second
using namespace std;
using ll = long long;
using ii = pair<int,int>;
using aa = array<int,3>; 
const int B=400;
vector<int> a[100005],adj[100005];
vector<ii> ans[100005];
int mp[100005]; 
int d[100005];
signed main() 
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    int n,m,q;
    cin >> n >> m >> q;
    for(int i=1;i<=m;i++) {
      int u,v;
      cin >> u >> v;
      adj[v].push_back(u);
    }
    for(int i=1;i<=n;i++) {
      ans[i].push_back({0,i});
      for(int v:adj[i]) {
        vector<ii> mer;
        int j=0;
        for(ii x:ans[i]) {
          while(j<ans[v].size() && make_pair(ans[v][j].fi+1,ans[v][j].se)>=x) {
            mer.push_back({ans[v][j].fi+1,ans[v][j].se});
            j++;
          }
          mer.push_back(x);
        }
        mer.erase(unique(mer.begin(),mer.end()),mer.end());
        while(mer.size()>B) mer.pop_back(); 
        ans[i]=mer;
      }
      //cout << i << endl;
      for(ii x:ans[i]) {
        //cout << x.fi << ' ' << x.se << endl;
      }
    }
    while(q--) {
      int u,k;
      cin >> u >> k;
      vector<int> sigma;
      for(int i=1;i<=k;i++) {
        int x;
        cin >> x;
        sigma.push_back(x);
        mp[x]=1;
      }
      if(k<B) {
        bool t=1;
        for(ii x:ans[u]) {
          if(!mp[x.se]) {
            cout << x.fi << '\n';
            t=0;
            break;
          }
        }
        if(t) {
          cout << "-1\n";
        }
      }
      else {
        for(int i=1;i<=u;i++) {
          if(mp[i]) d[i]=-1e9;
        } 
        
        for(int i=1;i<=u;i++) {
          for(int v:adj[i]) {
            d[i]=max(d[i],d[v]+1);
          }
        }
        if(d[u]<0) cout << "-1\n"; else
        cout << d[u] << '\n'; 
        for(int i=1;i<=u;i++) {
          d[i]=0;
        }
      }
      for(int x:sigma) {
        mp[x]=0;
      }
    }
    return 0;
}
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