#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 1e5 + 5, inf = 2e9;
int n, m, q;
vector <int> g[N], adj[N];
vector <pair<int, int>> luu[N];
int dp[N], c[N];
bool busy[N], seen[N];
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
// freopen(".INP", "r", stdin);
// freopen(".OUT", "w", stdout);
cin >> n >> m >> q;
while (m--) {
int u, v;
cin >> u >> v;
g[u].push_back(v);
adj[v].push_back(u);
}
int sq = 300;
for (int u=1;u<=n;++u) {
vector <pair<int, int>> tmp;
for (int v : adj[u]) {
for (pair <int, int> P : luu[v]) tmp.push_back(P);
tmp.emplace_back(0, v);
}
sort(tmp.begin(), tmp.end(), greater<>());
for (pair <int, int> P : tmp) {
if (!seen[P.second]) {
luu[u].emplace_back(P.first + 1, P.second);
seen[P.second] = 1;
if (luu[u].size() == sq) break;
}
}
for (pair <int, int> P : luu[u]) seen[P.second] = 0;
}
while (q--) {
int t, y, ans = -1;
cin >> t >> y;
for (int i=1;i<=y;++i) cin >> c[i], busy[c[i]] = 1;
if (!busy[t]) ans = 0;
if (y >= sq) {
fill(dp, dp+n+1, -inf);
dp[t] = 0;
for (int u=t;u>=1;--u) {
for (int v : adj[u]) dp[v] = max(dp[u] + 1, dp[v]);
}
for (int i=1;i<=t;++i) if (!busy[i]) ans = max(ans, dp[i]);
}
else {
for (pair <int, int> P : luu[t])
if (!busy[P.second]) ans = max(ans, P.first);
}
for (int i=1;i<=y;++i) busy[c[i]] = 0;
cout << ans << '\n';
}
}
