#include <iostream>
#include <cmath>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <string>
#include <cstring>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#define endl '\n'
using namespace std;
int n, m, q;
vector <int> v[100005];
void read()
{
cin >> n >> m >> q;
int x, y;
for(int i = 1; i <= m; i++)
{
cin >> x >> y;
v[y].push_back(x);
}
}
int d[100005];
void dfs(int beg, int cnt)
{
if(cnt > d[beg])
d[beg] = cnt;
for(int i = 0; i < v[beg].size(); i++)
{
dfs(v[beg][i], cnt+1);
}
}
int used[100005];
void solve_query()
{
for(int i = 1; i <= n; i++)
{
used[i] = 0;
d[i] = -1;
}
int t, y, x;
cin >> t >> y;
for(int i = 1; i <= y; i++)
{
cin >> x;
used[x] = 1;
}
vector <int> paths;
dfs(t, 0);
for(int i = 1; i <= n; i++)
{
if(d[i] != -1 && used[i] == 0)
paths.push_back(d[i]);
}
sort(paths.begin(), paths.end());
if(paths.size() == 0)
cout << -1 << endl;
else cout << paths[paths.size()-1] << endl;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
read();
for(int i = 1; i <= q; i++)
solve_query();
return 0;
}
