/**
* author minhnguyent546
* created_at Sat, 2025-01-11 17:02:51
* problem https://oj.uz/problem/view/JOI18_bitaro
**/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "cp/debug.h"
#else
#define debug(...)
#define cerr if (false) cerr
#endif
const int INF = 0x3f3f3f3f;
#ifdef LOCAL
const int thetaparacetamol = 2;
#else
const int thetaparacetamol = 399;
#endif
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
cin.exceptions(cin.failbit);
int n, m, q;
cin >> n >> m >> q;
vector<vector<int>> g(n);
vector<vector<int>> h(n);
vector<int> out_deg(n), in_deg(n);
vector<int> zero_out_deg_vers;
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
--u; --v;
assert(u < v);
g[u].emplace_back(v);
h[v].emplace_back(u);
out_deg[u]++;
in_deg[v]++;
}
for (int i = 0; i < n; ++i) {
if (out_deg[i] == 0) {
zero_out_deg_vers.emplace_back(i);
}
}
vector<vector<pair<int, int>>> furthest(n); // (ver, dist)
for (int i = 0; i < n; ++i) {
furthest[i].emplace_back(i, 0);
}
{
vector<int> dp(n);
vector<int> que;
for (int i = 0; i < n; ++i) {
if (in_deg[i] == 0) {
que.emplace_back(i);
}
}
vector<bool> seen(n);
for (int k = 0; k < (int) que.size(); ++k) {
int me = que[k];
int my_size = (int) furthest[me].size();
// cerr << "me = " << me + 1 << '\n';
for (int his : g[me]) {
vector<pair<int, int>> new_vers;
int my_ptr = 0, his_ptr = 0;
int his_size = (int) furthest[his].size();
while (my_ptr < my_size || his_ptr < his_size) {
if (his_ptr == his_size || (my_ptr < my_size && furthest[me][my_ptr].second + 1 > furthest[his][his_ptr].second)) {
if (!seen[furthest[me][my_ptr].first]) {
new_vers.emplace_back(furthest[me][my_ptr].first, furthest[me][my_ptr].second + 1);
seen[furthest[me][my_ptr].first] = true;
}
++my_ptr;
} else {
if (!seen[furthest[his][his_ptr].first]) {
new_vers.emplace_back(furthest[his][his_ptr]);
seen[furthest[his][his_ptr].first] = true;
}
++his_ptr;
}
if ((int) new_vers.size() == thetaparacetamol + 1) break;
}
for (auto [z, distance] : new_vers) {
seen[z] = false;
}
furthest[his].swap(new_vers);
if (--in_deg[his] == 0) {
que.emplace_back(his);
}
// cerr << "me = " << me + 1 << ", his = " << his + 1 << ", in_deg[his] = " << in_deg[his] << '\n';
}
}
}
vector<bool> go_out(n);
vector<int> vers(n);
vector<int> dp(n, -1);
#ifdef LOCAL
for (int ver = 0; ver < n; ++ver) {
cerr << "ver = " << ver + 1 << ": ";
for (auto [v, dist] : furthest[ver]) {
cerr << "(" << v + 1 << ", " << dist << ")" << ' ';
}
cerr << '\n';
}
#endif
for (int w = 0; w < q; ++w) {
int ver, num_vers;
cin >> ver >> num_vers;
--ver;
for (int i = 0; i < num_vers; ++i) {
int v;
cin >> v;
--v;
vers[i] = v;
go_out[v] = true;
}
if (num_vers > thetaparacetamol) {
fill(dp.begin(), dp.begin() + ver + 1, -1);
dp[ver] = 0;
auto cur_out_deg = out_deg;
vector<int> que = zero_out_deg_vers;
for (int k = 0; k < (int) que.size(); ++k) {
int u = que[k];
if (u == ver) continue;
for (int v : h[u]) {
--cur_out_deg[v];
if (v == ver) continue;
if (cur_out_deg[v] == 0) {
que.emplace_back(v);
}
}
}
assert(cur_out_deg[ver] == 0);
que = {ver};
for (int k = 0; k < (int) que.size(); ++k) {
int u = que[k];
for (int v : h[u]) {
dp[v] = max(dp[v], dp[u] + 1);
if (--cur_out_deg[v] == 0) {
que.emplace_back(v);
}
}
}
int ans = -1;
for (int i = 0; i <= ver; ++i) {
if (go_out[i]) continue;
ans = max(ans, dp[i]);
}
cout << ans << '\n';
} else {
int ans = -1;
for (int i = 0; i < (int) furthest[ver].size(); ++i) {
auto [z, distance] = furthest[ver][i];
if (!go_out[z]) {
ans = distance;
break;
}
}
cout << ans << '\n';
}
// reset
for (int i = 0; i < num_vers; ++i) {
go_out[vers[i]] = false;
}
}
return 0;
}
