#include<bits/stdc++.h>
using namespace std;
const int MAXN=1e5+6;
const int SQRT=110;
const int INF=2e9;
vector<int>g[MAXN];
vector<int>rg[MAXN];
vector<pair<int,int> >bestSQRT[MAXN];
bool no[MAXN];
int dist[MAXN],n,m,q;
bool c[MAXN];
/*bool cmp(pair<int,int> p1,pair<int,int> p2)
{
if(p1.second!=p2.second)return p1.second>p2.second;
return p1.first<p2.first;
}*/
int calc(int u)
{
for(int i=1;i<u;++i)
{
dist[i]=-INF;
}
dist[u]=0;
for(int i=u-1;i>=1;--i)
{
for(auto v:g[i])
{
if(v>u)continue;
dist[i]=max(dist[i],dist[v]+1);
}
}
int ret=-1;
for(int i=1;i<=u;++i)
{
if(no[i])continue;
ret=max(ret,dist[i]);
}
return ret;
}
vector<pair<int,int> >ivan;
void precompute()
{
for(int i=1;i<=n;++i)
{
ivan.clear();
ivan.push_back({0,i});
for(auto v:rg[i])
{
for(auto xd:bestSQRT[v])
{
ivan.push_back({-xd.first-1,xd.second});
}
}
sort(ivan.begin(),ivan.end());
for(auto xd:ivan)
{
if(c[xd.second])continue;
bestSQRT[i].push_back({-xd.first,xd.second});
if(bestSQRT[i].size()==SQRT)
{
break;
}
c[xd.second]=1;
}
for(auto xd:bestSQRT[i])
{
c[xd.second]=0;
}
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>n>>m>>q;
for(int i=0;i<m;++i)
{
int x,y;
cin>>x>>y;
g[x].push_back(y);
rg[y].push_back(x);
}
precompute();
/*for(int i=1;i<=n;i++)
{
cout<<i<<":\n";
for(auto xd:bestSQRT[i])
{
cout<<xd.first<<" "<<xd.second<<endl;
}
}*/
for(int i=1;i<=q;++i)
{
int x,y;
cin>>x>>y;
vector<int>busy;
for(int j=0;j<y;++j)
{
int f;
cin>>f;
busy.push_back(f);
no[f]=1;
}
if(y>=SQRT)
{
cout<<calc(x)<<"\n";
for(auto f:busy)
{
no[f]=0;
}
continue;
}
int ans=-1;
for(auto xd:bestSQRT[x])
{
if(no[xd.second])continue;
ans=xd.first;break;
}
if(ans!=-1)
{
cout<<ans<<"\n";
for(auto f:busy)
{
no[f]=0;
}
continue;
}
cout<<calc(x)<<"\n";
for(auto f:busy)
{
no[f]=0;
}
}
return 0;
}
