#include "bits/stdc++.h"
using namespace std;
using ll = long long;
const int SQRT = 350;
const int maxN = 1e5;
int dp[maxN + 5];
vector<int> adj[maxN + 5];
vector<pair<int, int>> root[maxN + 5];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// freopen("", "r", stdin);
// freopen("", "w", stdout);
int n, m, q; cin >> n >> m >> q;
for (int i = 0; i < m; i++) {
int a, b; cin >> a >> b;
adj[b].emplace_back(a);
}
vector<int> dist(n + 5, 0);
vector<int> seen(n + 5, -1);
for (int i = 1; i <= n; i++) {
vector<int> temp;
for (auto a : adj[i]) {
for (auto b : root[a]) {
int k = b.second, c = b.first;
if (seen[k] != i) {
seen[k] = i;
dist[k] = c + 1;
temp.push_back(k);
} else {
dist[k] = max(dist[k], c + 1);
}
}
if (seen[a] != i) {
temp.push_back(a);
dist[a] = 1;
seen[a] = i;
}
}
temp.push_back(i);
sort(temp.begin(), temp.end(), [&](int a, int b) {
return dist[a] > dist[b];
});
int sz = min(SQRT, (int) temp.size());
for (int j = 0; j < sz; j++) {
root[i].emplace_back(dist[temp[j]], temp[j]);
}
}
vector<int> invalid(n + 5, 0);
for (int i = 1; i <= q; i++) {
int x, y; cin >> x >> y;
for (int j = 0; j < y; j++) {
int cur; cin >> cur;
invalid[cur] = i;
}
if(x < SQRT) {
bool found = false;
for (auto a : root[x]) {
if (invalid[a.second] == i) continue;
found = true;
cout << a.first << "\n";
break;
}
if (!found) {
cout << -1 << "\n";
}
} else {
for (int j = 1; j <= n; j++) {
if (invalid[j] == i) dp[j] = -1;
else dp[j] = 0;
for (auto a : adj[j]) {
if (dp[a] >= 0) dp[j] = max(dp[j], dp[a] + 1);
}
}
cout << dp[x] << "\n";
}
}
}
