#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define ld long double
#define pii pair<int, int>
#define f first
#define s second
#define boost() cin.tie(0), cin.sync_with_stdio(0)
const int MN = 200005, BLK = 100;
int n, m, q, u, v, k, dp[MN];
vector<int> a[MN], r[MN];
vector<pii> far[MN];
int32_t main() {
boost();
cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
cin >> u >> v;
a[u].push_back(v);
r[v].push_back(u);
}
for (int i = 1; i <= n; i++) {
far[i].push_back({0, i});
for (int j : r[i]) for (pii p : far[j]) far[i].push_back({p.f + 1, p.s});
sort(far[i].begin(), far[i].end(), greater<>());
while (far[i].size() > BLK) far[i].pop_back();
}
for (int i = 1; i <= q; i++) {
cin >> u >> k;
set<int> s;
for (int j = 1; j <= k; j++) cin >> v, s.insert(v);
if (k >= BLK) {
int ans = -1;
dp[u] = 0;
if (!s.count(u)) ans = 0;
for (int j = u - 1; j > 0; j--) {
dp[j] = -0x3f3f3f3f;
for (int nxt : a[j]) if (nxt <= u) dp[j] = max(dp[j], dp[nxt] + 1);
if (!s.count(j)) ans = max(ans, dp[j]);
}
printf("%lld\n", ans);
} else {
int ans = -1;
for (pii p : far[u]) if (!s.count(p.s)) {ans = p.f; break;}
printf("%lld\n", ans);
}
}
return 0;
}
