#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
const int N=1e5+5,B=2001;
struct drum
{
int nod;
long long cost;
bool operator<(const drum &other)
{
return cost>other.cost;
}
};
vector<int>adj[N+1];
vector<drum>drumuri[N+1];
int n,m,q;
void read()
{
cin>>n>>m>>q;
for(int i=1;i<=m;i++)
{
int a,b;
cin>>a>>b;
adj[b].push_back(a);
}
}
void precalc()
{
vector<long long>best(n+1,-1);
for(int i=1;i<=n;i++)
{
vector<int>where;
drumuri[i].push_back({i,0});
for(auto u:adj[i])
{
for(auto [nod,dist]:drumuri[u])
{
if(best[nod]==-1)
{
where.push_back(nod);
best[nod]=dist+1;
}
else
{
best[nod]=max(best[nod],dist+1);
}
}
}
for(auto u:where)
{
drumuri[i].push_back({u,best[u]});
best[u]=-1;
}
sort(drumuri[i].begin(),drumuri[i].end());
while(drumuri[i].size()>B)
drumuri[i].pop_back();
}
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
read();
precalc();
vector<int>used(n+1,0);
vector<long long>best2(n+1,0);
for(int i=1;i<=q;i++)
{
int unde,cate;
cin>>unde>>cate;
vector<int>idx(cate+1);
for(int j=1;j<=cate;j++)
{
cin>>idx[j];
used[idx[j]]=true;
}
long long ans=-1;
if(cate>B)
{
for(int k=unde;k>=1;k--)
{
if(used[k]!=0)
ans=max(ans,best2[k]);
for(auto u:adj[k])
{
best2[u]=max(best2[u],best2[k]+1);
}
best2[k]=0;
}
}
else
{
for(auto [u,dist]:drumuri[unde])
{
if(!used[u])
ans=max(ans,dist);
}
}
for(int j=1;j<=cate;j++)
used[idx[j]]=false;
cout<<ans<<'\n';
}
//cout<<drumuri[5][0].cost<<'\n';
return 0;
}
