#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 10,b = 317;
int n,m,q,dp[maxn];
bool ocup[maxn];
vector<int> g[2][maxn];
vector<pair<int,int>> dist[maxn];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> m >> q;
for(int i = 1;i <= m;i++){
int u,v;
cin >> u >> v;
g[0][u].push_back(v);
g[1][v].push_back(u);
}
memset(dp,-1,sizeof dp);
for(int i = 1;i <= n;i++){
dist[i].push_back({0,i});
vector<int> calc;
for(int v : g[1][i])
for(auto [d,w] : dist[v]){
if(dp[w] == -1){
calc.push_back(w);
dp[w] = d + 1;
}
else dp[w] = max(dp[w],d + 1);
}
for(int j : calc){
dist[i].push_back({dp[j],j});
dp[j] = -1;
}
sort(dist[i].begin(),dist[i].end(),greater<>());
while((int) dist[i].size() > b) dist[i].pop_back();
}
while(q--){
int l,k,resp = -1;
cin >> l >> k;
vector<int> calc(k + 5);
for(int i = 1;i <= k;i++){
cin >> calc[i];
ocup[calc[i]] = 1;
}
if(k < b){
for(auto [d,i] : dist[l])
if(!ocup[i])
resp = max(resp,d);
}
else{
for(int u = 1;u <= l;u++)
dp[u] = 0;
for(int u = l;u > 0;u--){
for(int v : g[1][u]){
dp[v] = max(dp[v],dp[u] + 1);
if(!ocup[v]) resp = max(resp,dp[v]);
}
}
}
cout << resp << "\n";
for(int i : calc)
ocup[i] = 0;
}
return 0;
}
