#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define ll long long
#define nl "\n"
#define all(v) v.begin(),v.end()
#define baraa ios_base::sync_with_stdio(false);cin.tie(NULL);
using namespace std;
const ll BLK = 300;
int main() {
baraa
ll n, m, q;
cin >> n >> m >> q;
vector<ll> adj[n + 1], have(n + 1, 1), vis(n + 1, -1);
ll vid = 0;
while (m--) {
ll u, v;
cin >> u >> v;
adj[v].push_back(u);
}
vector<array<ll, 2> > vals[n + 1];
for (ll u = 1; u <= n; u++) {
for (ll v: adj[u]) {
auto &a = vals[u];
auto &b = vals[v];
vector<array<ll, 2> > res;
auto push = [&](vector<array<ll, 2> > &c, ll idx) {
if (vis[c[idx][1]] != vid)res.push_back(c[idx]);
vis[c[idx][1]] = vid;
};
ll sz1 = a.size(), sz2 = b.size(), i = 0, j = 0;
while ((i < sz1 or j < sz2) and res.size() <= BLK) {
if (i == sz1)push(b, j++);
else if (j == sz2 or a[i] > b[j])push(a, i++);
else push(b, j++);
}
vals[u] = res;
vid++;
}
for (auto &[d, _]: vals[u])d++;
if (vals[u].size() <= BLK)
vals[u].push_back({0, u});
// cout << u << nl;
// for (auto &[d, node]: vals[u])
// cout << node << ' ' << d << nl;
}
while (q--) {
ll node, sz;
cin >> node >> sz;
vector<ll> nodes(sz);
for (auto &x: nodes)cin >> x, have[x] = 0;
ll res = -1;
if (sz >= BLK) {
vector<ll> dp(n + 1, -1e12);
dp[node] = 0;
for (ll u = node; u >= 1; u--) {
for (ll v: adj[u])
dp[v] = max(dp[v], dp[u] + 1);
if (have[u])
res = max(res, dp[u]);
}
} else {
for (auto [d, u]: vals[node])
if (have[u]) {
res = d;
break;
}
}
cout << res << nl;
for (auto &x: nodes)have[x] = 1;
}
return 0;
}
