#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 47
#endif
constexpr int B = 100;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m, q;
cin >> n >> m >> q;
vector<vector<int>> g(n);
for (int i = 0; i < m; i++) {
int x, y;
cin >> x >> y;
x--; y--;
g[y].push_back(x);
}
vector<vector<array<int, 2>>> f(n);
vector<int> dp(n, -1);
for (int i = 0; i < n; i++) {
f[i].push_back({0, i});
vector<int> pos;
for (int j : g[i]) {
for (auto [w, k] : f[j]) {
if (dp[k] == -1) {
dp[k] = w + 1;
pos.push_back(k);
} else {
dp[k] = max(dp[k], w + 1);
}
}
}
for (int j : pos) {
f[i].push_back({dp[j], j});
}
sort(f[i].rbegin(), f[i].rend());
while (f[i].size() > B) {
f[i].pop_back();
}
for (int j : pos) {
dp[j] = -1;
}
}
vector<bool> blocked(n);
while (q--) {
int t, k;
cin >> t >> k;
t--;
vector<int> y(k);
for (int i = 0; i < k; i++) {
cin >> y[i];
blocked[--y[i]] = true;
}
int ans = -1;
if (k >= B) {
vector<int> dp(t + 1, -1e9);
dp[t] = 0;
for (int i = t; i >= 0; i--) {
if (!blocked[i]) {
ans = max(ans, dp[i]);
}
for (int j : g[i]) {
dp[j] = min(dp[j], dp[i] + 1);
}
}
} else {
for (auto [x, u] : f[t]) {
if (!blocked[u]) {
ans = x;
break;
}
}
}
cout << ans << '\n';
for (int i : y) {
blocked[i] = false;
}
}
return 0;
}
