# include <iostream>
# include <vector>
# include <algorithm>
using namespace std;
const int MAX=1e5+11;
int n,m,q,bl_sz=250;
vector<int> adj[MAX];
void read()
{
cin>>n>>m>>q;
for(int i=1;i<=m;i++)
{
int u,v;
cin>>u>>v;
adj[v].push_back(u);
}
}
int used[MAX];
vector<pair<int,int>> dp[MAX];
void precalc()
{
for(int i=1;i<=n;i++)
{
vector<pair<int,int>> v;
v.push_back({0,i});
for(int nxt: adj[i])
{
for(pair<int,int> pa: dp[nxt]) v.push_back({pa.first+1,pa.second});
}
sort(v.begin(),v.end(),greater<pair<int,int>>());
for(pair<int,int> pa: v)
{
if(used[pa.second]==i) continue;
dp[i].push_back(pa);
used[pa.second]=i;
if((int)dp[i].size()==bl_sz) break;
}
//cout<<i<<":"<<"\n";
//for(pair<int,int> pa: dp[i]) cout<<pa.first<<" "<<pa.second<<"\n";
}
}
int banned[MAX];
bool ban[MAX];
void small(int u)
{
int ans=-1;
for(pair<int,int> pa: dp[u])
{
if(!ban[pa.second])
{
ans=pa.first;
break;
}
}
cout<<ans<<"\n";
}
int lg[MAX];
void big(int u)
{
for(int i=1;i<=u;i++) lg[i]=-1;
lg[u]=0;
for(int i=u;i>1;i--)
{
if(lg[i]==-1) continue;
for(int nxt: adj[i]) lg[nxt]=max(lg[nxt],lg[i]+1);
}
int ans=-1;
for(int i=1;i<=u;i++)
{
if(!ban[i]) ans=max(ans,lg[i]);
}
cout<<ans<<"\n";
}
void queries()
{
while(q--)
{
int t,k;
cin>>t>>k;
for(int i=1;i<=k;i++)
{
cin>>banned[i];
ban[banned[i]]=1;
}
if(k<bl_sz) small(t);
else big(t);
for(int i=1;i<=k;i++) ban[banned[i]]=0;
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
read();
precalc();
queries();
return 0;
}
