#include <iostream>
#include <vector>
using namespace std;
const int rt = -1;
const int INF = 1'000'000'000;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int N, M, Q;
cin >> N >> M >> Q;
vector<int> edge[1+N];
vector<int> rev_edge[1+N];
for(int j = 1; j <= M; j++)
{
int u, v;
cin >> u >> v;
edge[u].push_back(v);
rev_edge[v].push_back(u);
}
for(int q = 1; q <= Q; q++)
{
int T, Y;
cin >> T >> Y;
vector<int> C(Y);
for(int i = 0; i < Y; i++) cin >> C[i];
if(Y > rt)
{
vector<bool> excluded(1+N, 0);
for(int c:C) excluded[c] = 1;
vector<int> maxdist(1+N, -INF);
for(int i = 1; i <= T; i++)
{
if(!excluded[i]) maxdist[i] = 0;
for(int j: rev_edge[i]) maxdist[i] = max(maxdist[i], 1 + maxdist[j]);
}
if(maxdist[T] < 0) maxdist[T] = -1;
cout << maxdist[T] << '\n';
}
else
{
cout << "!\n";
}
}
}
