#include<bits/stdc++.h>
#define int long long
using namespace std;
const int B = 320;
bool apagados[100010];
int dp[100010];
int n,m,q;
bool comp(pair<int,int> a , pair<int,int> b){
if(a.first < b.first){
return false;
}
if(a.first > b.first){
return true;
}
return (a.second < b.second);
}
vector<int> adj[100010];
signed main(){
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m >> q;
for(int i = 1;i <= m;i++){
int a,b;
cin >> a >> b;
adj[b].push_back(a);
}
vector<pair<int,int>> dist[100010];
for(int i = 1;i <= n;i++){
dist[i].push_back({0 , i});
}
for(int i = 1;i <= n;i++){
for(auto u : adj[i]){
vector<pair<int,int>> c,d;
c.clear();
for(auto l : dist[u]){
c.push_back({l.first + 1,l.second});
}
d = dist[i];
dist[i].clear();
set_union(d.begin() , d.end(), c.begin(), c.end(), back_inserter(dist[i]), comp);
if(dist[i].size() > B + 1){
dist[i].resize(B + 1);
}
}
}
for(int i = 1;i <= n;i++){
dist[i].push_back({-1 , 0});
}
for(int i = 1;i <= q;i++){
int t,y;
cin >> t >> y;
vector<int> atual;
for(int j = 1;j <= y;j++){
int a;
cin >> a;
atual.push_back(a);
apagados[a] = true;
}
if(y <= B){
for(auto u : dist[t]){
if(!apagados[u.second]){
cout << u.first << "\n";
break;
}
}
}
else{
int ans = -1;
for(int i = 1;i <= n;i++){
dp[i] = 0;
}
for(int i = t;i <= n;i++){
for(auto u : adj[i]){
dp[u] = max(dp[u] , dp[i] + 1);
}
if(!apagados[i]){
ans = max(ans , dp[i]);
}
}
cout << ans << "\n";
}
for(auto u : atual){
apagados[u] = false;
}
atual.clear();
}
}
