#include "bits/stdc++.h"
using namespace std;
using ll = long long;
const int SQRT = 300;
vector<int> adj[100005];
int seen[100005];
int dist[100005];
int invalid[100005];
int dp[100005];
vector<pair<int, int>> root[100005];
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].push_back(a);
}
for (int i = 1; i <= n; i++) {
vector<int> temp;
for (auto a : adj[i]) {
for (auto b : root[a]) {
if (seen[b.second] != i) {
seen[b.second] = i;
dist[b.second] = b.first + 1;
temp.push_back(b.second);
} else {
dist[b.second] = max(dist[b.second], b.first + 1);
}
}
if (seen[a] != i) {
temp.push_back(a);
dist[a] = 1;
seen[a] = i;
}
}
temp.push_back(i);
dist[i] = 0;
sort(temp.begin(), temp.end(), [](int a, int b) {
return dist[a] > dist[b];
});
for (int j = 0; j < min(SQRT, (int) temp.size()); j++) {
root[i].push_back({dist[temp[j]], temp[j]});
}
}
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]) dp[j] = max(dp[j], dp[a] + 1);
}
cout << dp[x] << "\n";
}
}
}
