// #include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <map>
#include <vector>
#include <iomanip>
#include <string>
#include <queue>
#include <set>
#include <deque>
#include <numeric>
#include <cassert>
#include <chrono>
using namespace std;
void fast_io(){
// freopen("", "r", stdin);
// freopen("", "w", stdout);
ios::sync_with_stdio(0);
cin.tie(); cout.tie();
cout << setprecision(9);
}
#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define fi first
#define se second
const int N = 1e5 + 5;
int n, m, q, indeg[N], ans[N];
bool vis[N];
vector<int> topo, adj[N];
vector<pair<int, int>> L[N];
vector<pair<int, int>> merge(vector<pair<int, int>> x, vector<pair<int, int>> y){
vector<pair<int, int>> z;
int i = 0, j = 0;
while (i < (int) x.size() && j < (int) y.size() && z.size() < 100){
if (x[i].fi + 1 > y[j].fi) {
if (vis[x[i].se]) i++;
else {
z.push_back({x[i].fi + 1, x[i].se});
vis[x[i].se] = 1;
i++;
}
}
else {
if (vis[y[j].se]) j++;
else{
z.push_back(y[j]);
vis[y[j].se] = 1;
j++;
}
}
}
while (i < (int) x.size()) {
if (vis[x[i].se]) i++;
else {
z.push_back({x[i].fi + 1, x[i].se});
vis[x[i].se] = 1;
i++;
}
}
while (j < (int) y.size()) {
if (vis[y[j].se]) j++;
else{
z.push_back(y[j]);
vis[y[j].se] = 1;
j++;
}
}
for (auto i : z) vis[i.se] = 0;
return z;
}
void init(){
queue<int> q;
for (int i = 1; i <= n; i++) L[i].push_back({0, i});
for (int i = 1; i <= n; i++) if (indeg[i] == 0) q.push(i);
while (q.size()){
int u = q.front(); q.pop();
topo.push_back(u);
for (auto v : adj[u]){
indeg[v]--;
if (indeg[v] == 0) q.push(v);
}
}
for (auto u : topo){
for (auto v : adj[u]){
L[v] = merge(L[u], L[v]);
}
}
}
void solve() {
cin >> n >> m >> q;
for (int i = 1; i <= m; i++){
int u, v; cin >> u >> v;
indeg[v]++;
adj[u].push_back(v);
}
init();
for (int Q = 1; Q <= q; Q++){
int T, Y; cin >> T >> Y;
int C[Y + 1];
map<int, bool> c;
for (int i = 1; i <= Y; i++) {
cin >> C[i];
c[C[i]] = 1;
}
if (Y < 100)
{
bool bb = 0;
int S = min(100, (int) L[T].size());
for (int i = 0; i < S; i++){
if (!c[L[T][i].second]){
cout << L[T][i].first << endl;
bb = 1;
break;
}
}
if (!bb) cout << -1 << endl;
}
else
{
for (int i = 1; i <= n; i++) ans[i] = 0;
for (int i = 1; i <= Y; i++){
ans[C[i]] = -1e9;
}
for (auto u : topo){
for (auto v : adj[u]){
if (ans[u] < 0) continue;
ans[v] = max(ans[v], ans[u] + 1);
}
}
if (ans[T] < 0) cout << -1 << endl;
else cout << ans[T] << endl;
}
}
return;
}
signed main() {
fast_io();
srand(chrono::steady_clock::now().time_since_epoch().count());
int tc = 1;
// cin >> tc;
while (tc--) solve();
return 0;
}
