#include <bits/stdc++.h>
using namespace std;
#define dbg(x) cerr << #x << ": " << x << endl;
const int MAX_N = 1e5 + 5;
const int MAX_K = 150;
const int INF = 1e9;
vector<int> g[MAX_N];
vector<int> gt[MAX_N];
bool block[MAX_N];
int used[MAX_N];
vector<pair<int, int>> paths[MAX_N];
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n, m, q;
cin >> n >> m >> q;
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
--u, --v;
g[u].push_back(v);
gt[v].push_back(u);
}
fill_n(used, MAX_N, -1);
for (int v = 0; v < n; ++v) {
for (auto u : gt[v]) {
for (const auto& [u1, x] : paths[u]) {
if (used[u1] == -1) {
used[u1] = paths[v].size();
paths[v].emplace_back(u1, x + 1);
} else {
paths[v][used[u1]].second = max(paths[v][used[u1]].second, x + 1);
}
}
sort(paths[v].rbegin(), paths[v].rend(), [&](const auto& lhs, const auto& rhs) {
return tie(lhs.second, lhs.first) < tie(rhs.second, rhs.first);
});
while (paths[v].size() > MAX_K) {
used[paths[v].back().first] = -1;
paths[v].pop_back();
}
for (int i = 0; i < (int)paths[v].size(); ++i) {
const auto& [u1, x] = paths[v][i];
used[u1] = i;
}
}
if (paths[v].size() < MAX_K) {
paths[v].emplace_back(v, 0);
}
for (const auto& [u, x] : paths[v]) {
used[u] = -1;
}
}
while (q--) {
int s;
cin >> s;
--s;
int k;
cin >> k;
int res = -INF;
vector<int> curr(k);
for (int i = 0; i < k; ++i) {
int v;
cin >> v;
--v;
curr[i] = v;
block[v] = true;
}
if (k >= MAX_K) {
vector<int> dp(n, -INF);
dp[s] = 0;
for (int v = s - 1; v >= 0; --v) {
for (auto u : g[v]) {
if (dp[u] == -INF) continue;
dp[v] = max(dp[v], dp[u] + 1);
}
}
for (int v = 0; v < n; ++v) {
if (block[v]) continue;
res = max(res, dp[v]);
}
} else {
for (const auto& [v, x] : paths[s]) {
if (block[v]) continue;
res = max(res, x);
}
}
if (res == -INF) {
cout << "-1\n";
} else {
cout << res << '\n';
}
for (auto v : curr) {
block[v] = false;
}
}
return 0;
}
