#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>
#include <cassert>
#include <cmath>
#include <stack>
#include <set>
#include <functional>
#include <bitset>
#include <map>
#include <unordered_map>
#include <queue>
#include <array>
#include <numeric>
#include <complex>
using namespace std;
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename A> ostream& operator<<(ostream& os, vector<A>& a) { for(auto &c:a)os<<c<<' '; return os;}
template<typename A> istream& operator>>(istream& os, vector<A>& a) { for(auto &c:a)os>>c; return os;}
template<typename A,size_t N> istream& operator>>(istream &os, array<A,N>&a) { for(auto &c:a)os>>c; return os;}
template<typename A,typename B> istream& operator>>(istream& os, pair<A,B>&a) { os>>a.first>>a.second; return os;}
template<typename A> istream& operator >>(istream& os,complex<A>& a){pair<A,A>aux;os>>aux;a=complex<A>(aux.first,aux.second);return os;}
#define bug(a) cerr << "(" << #a << ": " << a << ")\n";
#define all(x) x.begin(),x.end()
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define PQ priority_queue
#define x real
#define y imag
using pii= pair<int,int>;
using VI= vector<int>;
using v64= vector<int64_t>;
using point=complex<double>;
using i64= int64_t;
using i16= int16_t;
using u64= uint64_t;
using u32= uint32_t;
using i32= int32_t;
using u16= uint16_t;
const i32 inf=1e9;
const i64 INF=1e18;
const int mod=1e9+7;
const int sigma=26;
void solve()
{
int n,m,q;
cin>>n>>m>>q;
const int sq=150;//int(sqrt(n));
vector<vector<int>>g(n);
for(int i=0;i<m;i++)
{
int x,y;
cin>>x>>y;
g[y-1].pb(x-1);
}
vector<vector<pii>>best(n);
vector<int>val(n,-1);
//(m+n) * sq *log(sq*(m+n))
for(int i=0;i<n;i++)
{
vector<int>aux;
aux.pb(i);
val[i]=0;
for(auto &v:g[i])
{
for(auto &c:best[v])
{
aux.pb(c.first);
val[c.first]=max(val[c.first],c.second+1);
}
}
sort(all(aux));
aux.erase(unique(all(aux)),aux.end());
sort(all(aux),[&](int x,int y){
return val[x]>val[y];
});
for(auto &c:aux)
{
if(best[i].size()<sq)
best[i].pb({c,val[c]});
val[c]=-1;
}
}
vector<bool>viz(n,0);
while(q--)
{
int x,cnt;
cin>>x>>cnt;
x--;
vector<int>a(cnt);
cin>>a;
for(auto &c:a)
c--;
for(auto &c:a)
viz[c]=true;
int rez=-1;
if(cnt<sq)
{
for(auto &c:best[x])
{
if(!viz[c.first])
rez=max(rez,c.second);
}
}
else
{
vector<int>dp(x+1,-inf);
for(int i=0;i<=x;i++)
{
if(!viz[i])
dp[i]=0;
for(auto &c:g[i])
{
dp[i]=max(dp[i],dp[c]+1);
}
}
rez=max(dp[x],-1);
}
cout<<rez<<'\n';
for(auto &c:a)
viz[c]=false;
}
}
main()
{
i32 tt=1;
ios::sync_with_stdio(false);
cin.tie(0);
//cin>>tt;
while(tt--)
{
solve();
}
}
