#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
vector <int> v[100006];
int i,j,p,q,n,m,k,y,t;
int Q;
vector <pair <int,int>> best[100006];
const int crit = 450;
int used[100006];
int dp[100006];
int covered[100006];
int dfs(int u)
{
if(covered[u]==Q+1)
return dp[u];
covered[u]=Q+1;
dp[u]=-1;
if(used[u]!=Q+1)dp[u]=0;
for(auto j:v[u])
{
int val = dfs(j);
if(val!=-1)
dp[u]=max(dp[u],1+val);
}
return dp[u];
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>n>>m>>Q;
for(i=1; i<=m; i++)
{
cin>>p>>q;
v[q].push_back(p);
}
for(i=1; i<=n; i++)
{
for(auto j:v[i])
{
best[i].push_back({-1,j});
for(auto k:best[j])
best[i].push_back({k.first-1,k.second});
}
if(!best[i].empty())
{
sort(best[i].begin(),best[i].end());
while(best[i].size()>crit)
best[i].pop_back();
}
}
while(Q--)
{
int party;
cin>>party;
cin>>y;
for(i=1; i<=y; i++)
{
cin>>t;
used[t]=Q+1;
}
bool fl=0;
if(!best[party].empty()){
for(i=0; i<(int)best[party].size(); i++)
{
if(used[best[party][i].second]!=Q+1)
{
cout<<-best[party][i].first<<endl;
fl=1;
break;
}
}
}
if(fl)continue;
if(y<crit)
{
if(used[party]==Q+1)
cout<<-1<<endl;
else cout<<0<<endl;
continue;
}
cout<<dfs(party)<<endl;
}
return 0;
}
