#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);
}
vector<int>dist(n + 1, -1);
for(int i = 1;i <= n;++i){
D[i].push_back({0, i});
vector<int>nodes;
for(int j : G[i]){
for(auto T : D[j]){
int d = T.first + 1, nd = T.second;
if(dist[nd] == -1){
nodes.push_back(nd);
dist[nd] = d;
}
else{
dist[nd] = max(dist[nd], d);
}
}
}
for(int j : nodes){
D[i].push_back({dist[j], j});
}
sort(D[i].rbegin(), D[i].rend());
while(D[i].size() > B + 1){
D[i].pop_back();
}
for(int j : nodes){
dist[j] = -1;
}
}
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';
}
}
