#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ar array
#define debug(x) cerr << "[" << #x << "] = [" << x << "]\n"
template<class A, class B> ostream& operator<< (ostream& out, pair<A, B> p) {
return out << '[' << p.first << ", " << p.second << ']';
}
template<class A, int sz> ostream& operator<< (ostream& out, ar<A, sz> a) {
out << '[';
for (int i = 0; i < sz; ++i) {
if (i > 0) out << ", ";
out << a[i];
}
return out << ']';
}
template<class T> ostream& operator<< (ostream& out, vector<T>& v) {
out << '[';
for (int i = 0; i < v.size(); ++i) {
if (i > 0) {
out << ", ";
}
out << v[i];
}
return out << ']';
}
const int mxN = 100000;
const int B = 350;
int n, m, q;
bool vis[mxN], bad[mxN];
vector<int> adj[mxN];
vector<pair<int, int>> best[mxN]; // {distance, node}
vector<pair<int, int>> bfs(int start) { // lets fucking nuke this
vector<int> d(start + 1, -696969);
d[start] = 0;
vector<pair<int, int>> res;
for (int i = start; i >= 0; --i) {
if (d[i] < 0) continue;
res.emplace_back(d[i], i);
for (int j : adj[i]) {
d[j] = max(d[j], d[i] + 1);
}
}
return res;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m >> q;
for (int i = 0; i < m; ++i) {
int a, b; cin >> a >> b, --a, --b;
adj[b].push_back(a);
}
for (int i = 0; i < n; ++i) {
best[i].emplace_back(0, i);
for (int j : adj[i]) {
vector<pair<int, int>> nxt;
for (int a = 0, b = 0; nxt.size() < B && (a < best[i].size() || b < best[j].size());) {
if (b == best[j].size() || (a < best[i].size() && best[i][a] >= make_pair(best[j][b].first + 1, best[j][b].second))) {
if (!vis[best[i][a].second]) {
nxt.emplace_back(best[i][a].first, best[i][a].second);
vis[best[i][a].second] = 1;
}
++a;
}
else if (a == best[i].size() || (b < best[j].size() && make_pair(best[j][b].first + 1, best[j][b].second) > best[i][a])) {
if (!vis[best[j][b].second]) {
nxt.emplace_back(best[j][b].first + 1, best[j][b].second);
vis[best[j][b].second] = 1;
}
++b;
}
else assert(0);
}
for (auto& x : nxt) vis[x.second] = 0;
swap(best[i], nxt);
}
//debug(best[i]);
}
while(q--) {
int t, y; cin >> t >> y, --t;
vector<int> cur_bad(y);
for (int i = 0; i < y; ++i) {
cin >> cur_bad[i], --cur_bad[i];
bad[cur_bad[i]] = 1;
}
if (y < B) {
int ans = -1;
for (pair<int, int>& p : best[t]) {
if (!bad[p.second]) {
ans = p.first;
break;
}
}
cout << ans << "\n";
}
else {
int ans = -1;
vector<pair<int, int>> cur = bfs(t); // NUKE
//debug(cur);
for (pair<int, int>& p : cur) {
if (!bad[p.second]) {
ans = max(ans, p.first);
}
}
cout << ans << "\n";
}
for (int i : cur_bad) bad[i] = 0;
}
return 0;
}
