#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize ("Ofast")
#define all(x) x.begin() , x.end()
#define sze(x) (ll)(x.size())
#define mp(x , y) make_pair(x , y)
#define wall cout<<"--------------------------------------\n";
typedef long long int ll;
typedef pair<ll , ll> pll;
typedef pair<int , int> pii;
typedef double db;
typedef pair<pll , ll> plll;
typedef pair<int , pii> piii;
typedef pair<pll , pll> pllll;
const ll maxn = 1e5 + 18 , md = 1e9 + 7 , inf = 2e8;
int n , m , q , sq;
vector<int> adj[maxn] , qu;
vector<pii> f[maxn];
bool mark[maxn];
int dp[maxn];
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin>>n>>m>>q; sq = min(n , 300);
for(int i = 0 ; i < m ; i++){
int v , u;
cin>>v>>u; v--; u--;
adj[u].push_back(v);
}
for(int i = 0 ; i < n ; i++){
vector<pii> tmp;
tmp.push_back({-1 , i});
for(auto j : adj[i]){
for(auto k : f[j]){
tmp.push_back(k);
}
}
sort(all(tmp) , greater<pii>());
for(auto p : tmp){
if(sze(f[i]) == sq) break;
if(mark[p.second]) continue;
mark[p.second] = true;
f[i].push_back({p.first + 1 , p.second});
}
for(auto p : f[i]){
mark[p.second] = false;
}
}
for(int e = 0 ; e < q ; e++){
qu.clear();
int v , k , res = -1;
cin>>v>>k; v--;
for(int i = 0 ; i < k ; i++){
int u;
cin>>u; u--;
qu.push_back(u);
mark[u] = true;
}
if(k < sq){
for(auto p : f[v]){
if(mark[p.second]) continue;
res = p.first;
break;
}
} else {
for(int i = 0 ; i <= v ; i++){
int h = (mark[i] ? -inf : 0);
for(auto j : adj[i]){
h = max(dp[j] + 1 , h);
}
dp[i] = h;
}
res = (dp[v] < 0 ? -1 : dp[v]);
}
cout<<res<<'\n';
for(auto u : qu){
mark[u] = false;
}
}
return 0;
}
