#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
const int B = 50; /// ?
vector<int> G[N];
vector<pair<int, int>> D[N];
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, m, q;
cin >> n >> m >> q;
for(int i = 0;i < m;++i){
int u, v;
cin >> u >> v;
G[v].push_back(u);
}
for(int i = 1;i <= n;++i){
multiset<array<int, 4>>ms;
for(int j : G[i]){
ms.insert({D[j][0].first + 1, D[j][0].second, j, 0});
}
while(!ms.empty()){
int d = (*(--ms.end()))[0], node = (*(--ms.end()))[1], nd = (*(--ms.end()))[2], p = (*(--ms.end()))[3];
D[i].push_back({d, node});
ms.erase(--ms.end());
if((int)D[nd].size() != p + 1){
ms.insert({D[nd][p + 1].first + 1, D[nd][p + 1].second, nd, p + 1});
}
}
D[i].push_back({0, i});
while(D[i].size() > B + 1){
D[i].pop_back();
}
}
for(int i = 0;i < q;++i){
int t, k;
cin >> t >> k;
set<int>v;
for(int i = 0;i < k;++i){
int a;
cin >> a;
v.insert(a);
}
int res = -1;
if(k > B){
vector<int>dp(n + 1, -1e9);
dp[t] = 0;
for(int i = t;i >= 1;--i){
for(int j : G[i]){
dp[j] = max(dp[j], dp[i] + 1);
}
}
for(int i = 1;i <= t;++i){
if(v.find(i) == v.end())res = max(res, dp[i]);
}
}
else{
for(int i = 0;i < (int)D[t].size();++i){
int d = D[t][i].first, nd = D[t][i].second;
if(v.find(nd) == v.end())res = max(res, d);
}
}
cout << res << '\n';
}
}
