#include <bits/stdc++.h>

using namespace std;

const int N = (int) 1e5 + 10;
const int C = 100;

const int INF = (int) 1e9;

set<pair<int, int>> biggest[N];

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    int n, m, q;
    cin >> n >> m >> q;
    vector<int> rev_g[n];
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        rev_g[v - 1].emplace_back(u - 1);
    }
    set<int> was;
    int dist[n];
    for (int i = 0; i < n; i++) dist[i] = 0;
    for (int i = 0; i < n; i++) {
        biggest[i].insert({0, i});
        was.clear();
        dist[i] = 0;
        was.insert(i);
        for (int j: rev_g[i]) {
            for (auto [c, ind]: biggest[j]) {
                if (was.find(ind) != was.end()) {
                    if (dist[ind] < c + 1) {
                        biggest[i].erase({dist[ind], ind});
                        dist[ind] = c + 1;
                        biggest[i].insert({c + 1, ind});
                    }
                } else {
                    biggest[i].insert({c + 1, ind});
                    was.insert(ind), dist[ind] = c + 1;
                }
                if ((int) biggest[i].size() > C) {
                    dist[biggest[i].begin()->second] = 0;
                    biggest[i].erase(biggest[i].begin());
                }
            }
        }
        for (auto [c, ind]: biggest[i]) dist[ind] = 0;
    }
    for (int _ = 0; _ < q; _++) {
        int T, Y;
        cin >> T >> Y;
        T--;
        set<int> block;
        for (int i = 0; i < Y; i++) {
            int A;
            cin >> A;
            block.insert(A - 1);
        }
        if (Y >= C) {
            int dp[n];
            for (int i = 0; i < n; i++) dp[i] = -INF;
            dp[T] = 0;
            for (int i = T; i >= 0; i--) {
                for (int j: rev_g[i])
                    dp[j] = max(dp[j], dp[i] + 1);
            }
            int res = -1;
            for (int i = 0; i < n; i++) if (block.find(i) == block.end()) res = max(res, dp[i]);
            cout << res << "\n";
            continue;
        } else {
            int res = -1;
            for (auto [val, ind]: biggest[T]) {
                if (block.find(ind) == block.end())
                    res = max(res, val);
            }
            cout << res << "\n";
        }
    }
    return 0;
}