#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,sse,sse2,sse4,popcnt")
#include <bits/stdc++.h>
using namespace std;
constexpr int K = 200;
vector<pair<int, int>> buffer[100005];
bool seen[100005];
bool bruh[100005];
int dist[100005];
vector<int> topsort;
vector<int> adj[100005];
vector<int> rev[100005];
int freq[100005];
void push(int a, int b) {
for (auto [x, y]:buffer[a]) freq[y] = max(freq[y], x+1);
for (auto [x, y]:buffer[b]) freq[y] = max(freq[y], x);
vector<pair<int, int>> ans;
for (auto [x, y]:buffer[a]) if (freq[y] != -1) {
ans.push_back({freq[y], y});
freq[y] = -1;
}
for (auto [x, y]:buffer[b]) if (!freq[y] != -1) {
ans.push_back({freq[y], y});
freq[y] = 1;
}
sort(ans.begin(), ans.end());
swap(buffer[b], ans);
}
void dfs(int n) {
seen[n] = 1;
for (int i:adj[n]) if (!seen[i]) dfs(i);
topsort.push_back(n);
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
memset(freq, -1, sizeof(freq));
int N, M, Q;
cin >> N >> M >> Q;
for (int i = 1; i <= N; i ++) {
buffer[i].push_back({0, i});
}
for (int i = 1; i <= M; i ++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
rev[b].push_back(a);
}
for (int i = 1; i <= N; i ++) if (!seen[i]) dfs(i);
reverse(topsort.begin(), topsort.end());
for (int i:topsort) for (int j:adj[i]) push(i, j);
reverse(topsort.begin(), topsort.end());
for (int i = 1; i <= N; i ++) reverse(buffer[i].begin(), buffer[i].end());
for (int i = 1; i <= Q; i ++) {
int T, Y;
cin >> T >> Y;
vector<int> banned(Y);
for (int &j:banned) {
cin >> j;
bruh[j] = 1;
}
if (Y <= K) {
bool skip = 0;
for (auto [a, b]:buffer[T]) if (!bruh[b]) {
cout << a << "\n";
skip = 1;
break;
}
if (!skip) cout << "-1\n";
} else {
memset(dist, -0x3f, sizeof(dist));
dist[T] = 0;
int ans = -1;
for (int j:topsort) {
for (int k:rev[j]) dist[k] = max(dist[k], dist[j] + 1);
if (!bruh[j]) ans = max(ans, dist[j]);
}
cout << ans << "\n";
}
for (int j:banned) bruh[j] = 0;
}
}
