#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100005;
const int SQRT = MAXN / log2(MAXN) + 1;
int N, M, Q;
vector<int> radj[MAXN];
int vis[MAXN], mark = 0;
int dp[MAXN];
bool cannot_visit[MAXN];
vector<pair<int, int>> ans[MAXN]; // sqrt N longest paths from a vertex (city, length)
void Read() {
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
cin >> N >> M >> Q;
for (int i = 0; i < M; i++) {
int S, E;
cin >> S >> E;
radj[E].emplace_back(S);
}
}
void Preprocess(int n) {
if (vis[n] == mark) return;
vis[n] = mark;
ans[n].emplace_back(n, 0);
for (auto i : radj[n]) {
Preprocess(i);
for (auto j : ans[i]) {
ans[n].emplace_back(j.first, j.second + 1);
}
}
sort(begin(ans[n]), end(ans[n]), [&](const pair<int, int> &a, const pair<int, int> &b) {
return a.first < b.first || (a.first == b.first && a.second > b.second);
});
ans[n].resize(unique(begin(ans[n]), end(ans[n]), [&](const pair<int, int> &a, const pair<int, int> &b) {
return a.first == b.first;
}) - begin(ans[n]));
sort(begin(ans[n]), end(ans[n]), [&](const pair<int, int> &a, const pair<int, int> &b) {
return a.second > b.second;
});
while (ans[n].size() > SQRT) ans[n].pop_back();
}
void Preprocess() {
mark++;
for (int i = 1; i <= N; i++) {
Preprocess(i);
}
}
void Dfs(int n) {
if (vis[n] == mark) return;
vis[n] = mark;
dp[n] = (cannot_visit[n] ? -1e9 : 0);
for (auto i : radj[n]) {
Dfs(i);
dp[n] = max(dp[n], dp[i] + 1);
}
}
void Solve() {
for (int i = 0; i < Q; i++) {
int T, Y;
cin >> T >> Y;
set<int> C;
while (Y--) {
int c;
cin >> c;
C.emplace(c);
cannot_visit[c] = true;
}
if (C.size() >= SQRT) {
mark++; Dfs(T);
cout << max(dp[T], -1) << "\n";
} else {
int res = -1;
for (int j = 0; j < ans[T].size(); j++) {
int u = ans[T][j].first;
if (C.count(u)) continue;
res = ans[T][j].second;
break;
}
cout << res << "\n";
}
for (auto c : C) {
cannot_visit[c] = false;
}
}
}
int main() {
Read();
Preprocess();
Solve();
return 0;
}
