#include<bits/stdc++.h>
using namespace std;
vector<int>qr[200005];
vector<int>adj[200005];
vector<int>rv[200005];
int vis[200005];
int ar[200005];
int cant[200005];
int n,m,q;
int mx[200005];
int root=320;
int inf=1e6;
int big(int x,vector<int>&v){
//cerr<<x<<":\n";
for(int i=1;i<=n;i++)mx[i]=-inf,cant[i]=0;
for(auto x:v)cant[x]=1;
mx[x]=0;
int ans=-1;
for(int i=x;i>=1;i--){
//cerr<<mx[i]<<" ";
if(!cant[i])ans=max(ans,mx[i]);
for(auto v:rv[i])mx[v]=max(mx[v],mx[i]+1);
}
for(auto x:v)cant[x]=0;
//cerr<<"\n";
return ans;
}
vector<pair<int,int>>tans[100005];
vector<pair<int,int>> merge(vector<pair<int,int>>a,vector<pair<int,int>>b){
vector<pair<int,int>>c;
vector<int>del;
int i=0,j=0;
//cerr<<"in merge\n";
while(i<a.size()||j<b.size()){
if(i==a.size()){
for(;j<b.size();j++)if(!vis[b[j].second])c.push_back(b[j]),vis[b[j].second]++,del.push_back(b[j].second);
break;
}
if(j==b.size()){
for(;i<a.size();i++)if(!vis[a[i].second])c.push_back(a[i]),vis[a[i].second]++,del.push_back(a[i].second);
break;
}
if(a[i]>b[j]){
if(!vis[a[i].second])c.push_back(a[i]),vis[a[i].second]++,del.push_back(a[i].second);
i++;
}
else{
if(!vis[b[j].second])c.push_back(b[j]),vis[b[j].second]++,del.push_back(b[j].second);
j++;
}
}
while(c.size()>root)c.pop_back();
for(auto x:del)vis[x]=0;
return c;
}
void upd(int x){
for(auto &p:tans[x])p.first++;
tans[x].push_back({0,x});
//cerr<<"tans "<<x<<"\n";
//for(auto v:tans[x])cerr<<v.first<<" "<<v.second<<"\n";
//cerr<<"upd work\n";
for(auto v:adj[x]){
tans[v]=merge(tans[v],tans[x]);
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cin>>n>>m>>q;
for(int i=0;i<m;i++){
int s,e;cin>>s>>e;
adj[s].push_back(e);
rv[e].push_back(s);
}
for(int i=0;i<q;i++){
int t,y;cin>>t>>y;
ar[i]=t;
for(int j=0;j<y;j++){
int x;cin>>x;
qr[i].push_back(x);
}
}
//cerr<<"work\n";
for(int i=1;i<=n;i++)upd(i);
//cerr<<"work\n";
for(int i=0;i<q;i++){
if(qr[i].size()>root){
cout<<big(ar[i],qr[i])<<"\n";
}else{
int ans=-1;
for(auto x:qr[i])cant[x]=1;
for(auto x:tans[ar[i]]){
if(!cant[x.second]){
ans=x.first;
break;
}
}
for(auto x:qr[i])cant[x]=0;
cout<<ans<<"\n";
}
}
}
