#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
typedef pair<ll, ll> pll;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define ms memset
#define pb push_back
#define F first
#define S second
ll MOD = 1000000007;
ll INF = 1000000000;
ll power(ll base, ll n){
if (n == 0) return 1;
if (n == 1) return base;
ll halfn = power(base, n/2);
if (n % 2 == 0) return (halfn * halfn) % MOD;
return (((halfn * halfn) % MOD) * base) % MOD;
}
ll inverse(ll n){
return power(n, MOD-2);
}
ll add(ll a, ll b){
return (a+b) % MOD;
}
ll mul(ll a, ll b){
return (a*b) % MOD;
}
ll gcd(ll a, ll b){
if (a == 0) return b;
if (a == 1) return 1;
return gcd(b%a, a);
}
int main(){
ios::sync_with_stdio(false);
int n, m, q; cin >> n >> m >> q;
vi g[n];
vii largest[n];
FOR(i, 0, m){
int s, e; cin >> s >> e;
g[e-1].pb(s-1);
}
vi used(n, -1);
FOR(i, 0, n){
vii all;
all.pb({0, i});
for (int u : g[i]){
for (ii node : largest[u]){
node.F++;
all.pb(node);
}
}
sort(all.begin(), all.end());
int len = all.size();
ROF(j, len-1, 0){
if (largest[i].size() > 100) break;
if (used[all[j].S] == i) continue;
used[all[j].S] = i;
largest[i].pb(all[j]);
}
}
vi invalid(n, -1);
FOR(j, 0, q){
int t, y; cin >> t >> y;
t--;
FOR(i, 0, y){
int c; cin >> c;
invalid[c-1] = j;
}
if (y > 100){
vi dp(t+1);
FOR(i, 0, t+1){
if (invalid[i] == j) dp[i] = -1;
for (int u : g[i]){
if (dp[u] == -1) continue;
dp[i] = max(dp[i], dp[u]+1);
}
}
cout << dp[t] << '\n';
}
else{
bool sol = true;
FOR(i, 0, largest[t].size()){
if (invalid[largest[t][i].S] != j){
cout << largest[t][i].F << '\n';
sol = false; break;
}
}
if (sol) cout << -1 << '\n';
}
}
}
