#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <bits/stdc++.h>
#define f first
#define s second
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
vector<vector<int>> adj;
vector<vector<int>> radj;
vector<vector<pair<int, int>>> best; // <val, node>
vector<int> bp;
int main() {
int n, m, q; cin >> n >> m >> q;
adj.resize(n);
radj.resize(n);
best.resize(n, vector<pair<int, int>>());
bp.resize(n, -1);
for (int i = 0; i < m; i++) {
int a, b; cin >> a >> b; --a; --b;
adj[a].push_back(b);
radj[b].push_back(a);
}
for (int i = 0; i < n; i++) {
best[i].push_back({0, i});
vector<int> in;
for (int x: radj[i]) {
for (pair<int, int> u: best[x]) {
if (u.f == -1) break;
if (bp[u.s] == -1) {
bp[u.s] = u.f+1;
in.push_back(u.s);
} else {
bp[u.s] = max(bp[u.s], u.f+1);
}
}
}
for (int x: in) {
best[i].push_back({bp[x], x});
}
sort(best[i].rbegin(), best[i].rend());
best[i].resize(100, {-1, -1});
for (int x: in) {
bp[x] = -1;
}
}
// for (int i = 0; i < n; i++) {
// for (auto j: best[i]) {
// cout << j.f << ", " << j.s << " ";
// }
// cout << "\n";
// cout << "\n";
// }
vector<bool> aggin(n);
for (int i = 0; i < q; i++) {
int a, t; cin >> a >> t; --a;
vector<int> clapped;
for (int i = 0; i < t; i++) {
int u; cin >> u; --u;
clapped.push_back(u);
aggin[u] = true;
}
if (t > 100) {
vector<int> dp(a+1, -1);
dp[a] = 0;
int ans = -1;
for (int i = a; i >= 0; i--) {
if (dp[i] == -1) { continue; }
if (!aggin[i]) { ans = max(ans, dp[i]); }
for (int x: radj[i]) { dp[x] = max(dp[x], dp[i] + 1); }
}
cout << ans << "\n";
} else {
bool nig = false;
for (pair<int, int> x: best[a]) {
if (x.s == -1) continue;
if (!aggin[x.s]) {
cout << x.f << "\n"; nig = true; break;
}
}
if (!nig) cout << -1 << "\n";
}
for (int u: clapped) {
aggin[u] = false;
}
}
}
