#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 7;
const int S = 100;
int x[N],block[N],from[N],n,m,q,dp[N];
vector<pair<int,int>> path[N];
vector<int> g[N];
void prep()
{
for(int i = 1; i <= n; i++)
{
path[i].push_back({0,i});
vector<int> node;
for(int j : g[i])
{
for(auto [len,o] : path[j])
{
if(from[o] == -1)
{
node.push_back(o);
from[o] = len+1;
}
else {
from[o] = max(from[o],len + 1);
}
}
}
for(int id : node) path[i].push_back({from[id],id});
sort(path[i].begin(),path[i].end(),greater<pair<int,int>>());
while(path[i].size() > S) path[i].pop_back();
for(int id : node) from[id] = -1;
}
}
int main()
{
cin >> n >> m >> q;
for(int i = 1; i <= n; i++) from[i] = -1;
for(int i = 1; i <= m; i++)
{
int u,v;
cin >> u >> v;
g[v].push_back(u);
}
prep();
while(q--)
{
int t,y;
cin >> t >> y;
for(int i = 1; i <= y; i++)
{
cin >> x[i];
block[x[i]] = 1;
}
int ans = -1;
if(y >= S)
{
for(int i = t; i >= 1; i--)
{
if(!block[i]) ans = max(ans,dp[i]);
for(int j : g[i]) dp[j] = max(dp[j],dp[i] + 1);
}
for(int i = 1; i <= n; i++) dp[i] = 0;
}
else
{
for(auto [len,o] : path[t])
{
// cout << o <<' '<< len << endl;
if(!block[o]) ans = max(ans,len);
}
}
for(int i = 1; i <= y; i++) block[x[i]] = 0;
cout << ans <<'\n';
}
}
