#include <bits/stdc++.h>
#define sz(x) (int)(x).size()
using namespace std;
const int N = 1e5+4, B = 316, INF = -1e9;
vector<int> to[N], from[N];
vector<array<int,2>> pre[N];
int ans[N];
bitset<N> d;
vector<array<int,2>> merge(vector<array<int,2>> v, vector<array<int,2>> w)
{
int x=0,y=0;
vector<array<int,2>> u;
while (x<sz(v)&&y<sz(w)&&sz(u)<B)
{
if (v[x][0]+1>w[y][0])
{
if (!d[v[x][1]])
{
d[v[x][1]]=1;
u.push_back({v[x][0]+1,v[x][1]});
}
++x;
}
else
{
if (!d[w[y][1]])
{
d[w[y][1]]=1;
u.push_back(w[y]);
}
++y;
}
}
while (x<sz(v)&&sz(u)<B)
{
if (!d[v[x][1]])
{
d[v[x][1]]=1;
u.push_back({v[x][0]+1,v[x][1]});
}
++x;
}
while (y<sz(w)&&sz(u)<B)
{
if (!d[w[y][1]])
{
d[w[y][1]]=1;
u.push_back(w[y]);
}
++y;
}
for (auto i : u)
d[i[1]]=0;
return u;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
int n,m,q,x,y,z,a;
cin>>n>>m>>q;
while (m--)
{
cin>>x>>y;
from[x].push_back(y);
to[y].push_back(x);
}
for (int i=1;i<=n;++i)
pre[i].push_back({0,i});
for (int i=1;i<=n;++i)
for (int j : from[i])
pre[j]=merge(pre[i],pre[j]);
// for (int i=1;i<=n;++i)
// {
// cout<<i<<":\n";
// for (auto j : pre[i])
// cout<<j[0]<<" "<<j[1]<<"\n";
// }
// return 0;
while (q--)
{
cin>>x>>y;
a=-1;
if (y<B)
{
vector<int> t(y);
for (int i=0;i<y;++i)
{
cin>>t[i];
d[t[i]]=1;
}
for (auto i : pre[x])
if (!d[i[1]])
a=max(a,i[0]);
for (int i : t)
d[i]=0;
}
else
{
for (int i=0;i<y;++i)
{
cin>>z;
if (z<=x)
d[z]=1;
}
for (int i=1;i<=x;++i)
ans[i]=INF;
ans[x]=0;
for (int i=x;i;--i)
{
if (!d[i])
a=max(a,ans[i]);
else
d[i]=0;
for (int j : to[i])
ans[j]=max(ans[j],ans[i]+1);
}
}
cout<<a<<"\n";
}
return 0;
}
