#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 10 , maxsq = 320;
int n , m , q , dis[maxn];
vector <int> g[maxn] , revg[maxn] , alldis[maxn];
vector <pair<int , int>> big_path[maxn] , all;
bool marked[maxn];
void merg(int a , int b)
{
vector <pair <int ,int> > res;
int pa = 0 , pb = 0 , sz = 0 , sza = big_path[a].size() , szb = big_path[b].size();
while(sz < maxsq)
{
if(pa == sza || pb == szb)
break;
if(big_path[b][pb].second >= big_path[a][pa].second)
{
if(!marked[big_path[b][pb].first])
{
marked[big_path[b][pb].first] = true;
res.push_back(make_pair(big_path[b][pb].first , big_path[b][pb].second + 1));
sz++;
}
pb++;
}
else
{
if(!marked[big_path[a][pa].first])
{
marked[big_path[a][pa].first] = true;
res.push_back(make_pair(big_path[a][pa].first , big_path[a][pa].second));
sz++;
}
pa++;
}
}
if(sz < maxsq)
{
while(pa < sza)
{
if(sz >= maxsq)
break;
if(!marked[big_path[a][pa].first])
{
marked[big_path[a][pa].first] = true;
res.push_back(make_pair(big_path[a][pa].first , big_path[a][pa].second));
sz++;
}
pa++;
}
while(pb < szb)
{
if(sz >= maxsq)
break;
if(!marked[big_path[b][pb].first])
{
marked[big_path[b][pb].first] = true;
res.push_back(make_pair(big_path[b][pb].first , big_path[b][pb].second + 1));
sz++;
}
pb++;
}
}
for(auto u : res)
marked[u.first] = false;
big_path[a].swap(res);
}
void find_path(int v)
{
for(int i = 0 ; i <= n ; i++)
{
dis[i] = -1 ;
alldis[i].clear();
}
dis[v] = 0;
alldis[0].push_back(v);
for(int i = v - 1 ; i > 0 ; i--)
{
for(auto u : g[i])
if(dis[u] > -1)
dis[i] = max(dis[i] , dis[u] + 1);
alldis[dis[i]].push_back(i);
}
for(int i = n ; i > -1 ; i--)
for(auto u : alldis[i])
all.push_back(make_pair(u , i));
}
int main()
{
cin >> n >> m >> q;
for(int i = 0 ; i < m ; i++)
{
int s , e;
cin >> s >> e;
//s = i + 1;
//e = i + 3;
g[s].push_back(e);
revg[e].push_back(s);
}
for(int i = 1 ; i <= n ; i++)
{
big_path[i].push_back(make_pair(i , 0));
for(auto u : revg[i])
merg(i , u);
}
while(q--)
{
int t , y;
cin >> t >> y;
vector <int> bad;
for(int i = 0 ; i < y ; i++)
{
int tmp;
cin >> tmp;
bad.push_back(tmp);
}
for(int i : bad)
marked[i] = true;
if(y < maxsq)
{
int ans = -1;
for(auto i : big_path[t])
{
if(!marked[i.first])
{
ans = i.second;
break;
}
}
cout << ans << endl;
}
else
{
all.clear();
find_path(t);
int ans = -1;
for(auto u : all)
{
if(!marked[u.first])
{
ans = u.second;
break;
}
}
cout << ans << endl;
}
for(auto i : bad)
marked[i] = false;
}
return 0;
}
