#include <bits/stdc++.h>
using namespace std;
const int kN = 1e5;
const int bucket = 50;
vector<int> gt[1 + kN];
vector<pair<int, int>> paths[1 + kN];
int vis[1 + kN], b[kN], dp[1 + kN];
bitset<1 + kN> blocked;
void maxSelf(int &x, int y) {
if (x < y) {
x = y;
}
}
void testCase() {
int n, m, q;
cin >> n >> m >> q;
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
gt[v].emplace_back(u);
}
for (int u = 1; u <= n; ++u) {
vector<pair<int, int>> aux{{0, u}};
for (int v : gt[u]) {
for (auto it : paths[v]) {
aux.emplace_back(it.first + 1, it.second);
}
}
sort(aux.begin(), aux.end(), greater<pair<int, int>>());
for (auto it : aux) {
if (vis[it.second] != u) {
paths[u].emplace_back(it);
if ((int)paths[u].size() == bucket) {
break;
}
vis[it.second] = u;
}
}
}
for (int i = 0; i < q; ++i) {
int s, m;
cin >> s >> m;
for (int j = 0; j < m; ++j) {
cin >> b[j];
blocked[b[j]] = true;
}
if (bucket <= m) {
for (int u = 1; u <= s; ++u) {
if (blocked[u]) {
dp[u] = -1;
} else {
dp[u] = 0;
}
for (int v : gt[u]) {
if (dp[v] != -1) {
maxSelf(dp[u], dp[v] + 1);
}
}
}
cout << dp[s] << '\n';
} else {
int ans = -1;
for (auto it : paths[s]) {
if (!blocked[it.second]) {
ans = it.first;
break;
}
}
cout << ans << '\n';
}
for (int j = 0; j < m; ++j) {
blocked[b[j]] = false;
}
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int tests = 1;
for (int tc = 0; tc < tests; ++tc) {
testCase();
}
return 0;
}
