#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
typedef long long ll;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
}
const int maxn = 1e5 + 10, block_size = sqrt(maxn);
int n, m, q, sp[maxn], dp[maxn];
vector < int > adj[maxn];
void input()
{
cin >> n >> m >> q;
for (int i = 1; i <= m; i ++)
{
int s, e;
cin >> s >> e;
adj[e].push_back(s);
}
}
void compute()
{
for (int i = 1; i <= n; i ++)
{
dp[i] = -1e9;
if (!sp[i])
dp[i] = 0;
for (int u : adj[i])
dp[i] = max(dp[i], dp[u] + 1);
}
}
void answer_queries()
{
for (int i = 1; i <= q; i ++)
{
int x, t;
cin >> t >> x;
vector < int > spec;
for (int j = 1; j <= x; j ++)
{
int y;
cin >> y;
spec.push_back(y);
sp[y] = 1;
}
compute();
if (dp[t] < 0)
cout << -1 << endl;
else
cout << dp[t] << endl;
for (int v : spec)
sp[v] = 0;
}
}
void solve()
{
input();
answer_queries();
}
int main()
{
speed();
solve();
return 0;
}
