#include <bits/stdc++.h>
using namespace std;
const long long mxN = 1e5+5;
const long long INF = 1e16;
const long long MOD = 1e9+7;
const long long SQRT = 100;
vector<long long> radj[mxN];
vector<pair<long long, long long>> paths[mxN];
#define endl '\n'
void solve(){
long long n,m,k;
cin >> n >> m >> k;
for(int i=0; i<m; i++){
long long a,b;
cin >> a >> b;
radj[b].push_back(a);
}
vector<long long> from(n+1,-1);
for(int i=1; i<=n; i++){
paths[i].push_back({0,i});
vector<long long> have;
for(auto prev : radj[i]){
for(auto p : paths[prev]){
if(from[p.second]==-1){
have.push_back(p.second);
from[p.second]=p.first+1;
}
else{
from[p.second]=max(from[p.second],p.first+1);
}
}
}
for(auto x : have){
paths[i].push_back({from[x],x});
}
sort(paths[i].rbegin(),paths[i].rend());
while(paths[i].size()>SQRT){
paths[i].pop_back();
}
for(auto x : have){
from[x]=-1;
}
}
vector<bool> blocked(n+1);
for(int i=0; i<k; i++){
long long t,y;
cin >> t >> y;
vector<long long> c(y);
for(int j=0; j<y; j++){
cin >> c[j];
blocked[c[j]]=true;
}
long long ans = -1;
if(y>=SQRT){
vector<long long> dp(t+1,-1);
dp[t]=0;
for(int i=t; i>=1; i--){
if(dp[i]==-1){
continue;
}
if(!blocked[i]){
ans=max(ans,dp[i]);
}
for(auto prev : radj[i]){
dp[prev]=max(dp[prev],dp[i]+1);
}
}
}
else{
for(auto [dist,idx] : paths[t]){
if(!blocked[idx]){
ans = dist;
break;
}
}
}
cout << ans << endl;
for(auto x : c){
blocked[x]=false;
}
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
long long t = 1; //cin >> t;
while(t--){
solve();
}
}
