#include <bits/stdc++.h>
using namespace std;
int32_t main()
{
cin.tie(0)->sync_with_stdio(0);
int n, m, q;
cin >> n >> m >> q;
vector<vector<int>> g(n + 1), gr(n + 1);
for(int i = 1; i <= m; i++) {
int a, b;
cin >> a >> b;
g[a].push_back(b);
gr[b].push_back(a);
}
const int sz = 250;
#define T vector<pair<int, int>>
vector<bool> used(n + 1);
auto merge = [&](T a, T b) {
T ret;
int j = 0;
for(int i = 0; i < (int)b.size(); i++) {
b[i].first++;
while(j < (int)a.size() && a[j].first >= b[i].first) {
if(used[a[j].second]) {
j++;
continue;
}
used[a[j].second] = 1;
ret.push_back(a[j++]);
}
if(used[b[i].second]) {
continue;
}
used[b[i].second] = 1;
ret.push_back(b[i]);
}
while(j < (int)a.size()) {
if(used[a[j].second]) {
j++;
continue;
}
used[a[j].second] = 1;
ret.push_back(a[j++]);
}
for(int i = 0; i < (int)ret.size(); i++) {
used[ret[i].second] = 0;
}
while((int)ret.size() > sz) {
ret.pop_back();
}
return ret;
};
vector<T> cand(n + 1);
for(int i = 1; i <= n; i++) {
cand[i].push_back({0, i});
for(int from : gr[i]) {
cand[i] = merge(cand[i], cand[from]);
}
}
const int oo = 1e9;
for(int i = 1; i <= q; i++) {
int v, k;
cin >> v >> k;
vector<int> cant(k + 1);
for(int j = 1; j <= k; j++) {
cin >> cant[j];
used[cant[j]] = 1;
}
int ans = -1;
if(k >= sz) {
vector<int> dp(n + 1, -oo);
dp[v] = 0;
for(int j = v; j >= 1; j--) {
for(int to : g[j]) {
dp[j] = max(dp[j], dp[to] + 1);
}
if(!used[j]) {
ans = max(ans, dp[j]);
}
}
}
else {
for(int j = 0; j < (int)cand[v].size(); j++) {
if(!used[cand[v][j].second]) {
ans = cand[v][j].first;
break;
}
}
}
cout << ans << '\n';
for(int j = 1; j <= k; j++) {
used[cant[j]] = 0;
}
}
}
