#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
// #pragma GCC target ("avx2")
// #pragma GCC optimize ("O3")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC optimize("fast-math")
#define ll long long
#define ld long double
#define vi vector<ll>
#define endl "\n"
#define pr pair<ll, ll>
#define ff first
#define ss second
#define all(x) x.begin(), x.end()
const int mod = 1e9+7;
void _p(ll a){cout<<a<<endl;}
void _p(string a){cout<<a<<endl;}
void _p(ld a) {cout<<a<<endl;}
template <class T>
void _p(vector<T> a){for(T val:a)cout<<val<<" ";cout<<endl;}
#define debug(x) cout<<#x<<" -> ";_p(x)
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update > ordered_set;
vector<pr> move8 = {{1, 0}, {1, 1}, {0, 1}, {-1, 1}, {-1, 0}, {-1, -1}, {0, -1}, {1, -1}};
vector<pr> move4 = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
vector<pr> move2 = {{0, 1}, {1, 0}};
void solution();
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
solution();
return 0;
}
const int MAXN = 1e5+10;
vi adj[MAXN];
ll n;
ll calculate(ll T, set<ll> &hs) {
vi dist(n+1, -1e18);
vector<bool> vis(n+1);
dist[T] = 0;
ll mx = -1e18;
priority_queue<pr> q;
q.push({0, T});
while (!q.empty()) {
ll a = q.top().ss; q.pop();
if (vis[a]) continue;
vis[a] = true;
for (auto b : adj[a]) {
if (dist[a] + 1 > dist[b]) {
dist[b] = dist[a] + 1;
q.push({dist[b], b});
}
}
}
for (int i = 1; i <= n; i++) {
if (hs.count(i)) continue;
mx = max(mx, dist[i]);
}
return mx;
}
void solution() {
ll m, q; cin >> n >> m >> q;
while (m--) {
ll a, b; cin >> a >> b;
adj[b].push_back(a);
}
while (q--) {
ll t, y; set<ll> hs;
cin >> t >> y;
while (y--) {
ll x; cin >> x;
hs.insert(x);
}
ll ans = calculate(t, hs);
cout << (ans == -1e18 ? -1 : ans) << endl;
}
}
