#include <bits/stdc++.h>
using namespace std;
#define task "test"
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)
#define sz(a) (int)(a).size()
#define all(a) (a).begin(), (a).end()
#define bit(s, i) (((s) >> (i)) & 1)
#define ii pair <int, int>
#define fi first
#define se second
#define ll long long
#define eb emplace_back
#define pb push_back
#define __builtin_popcount __builtin_popcountll
void solve();
int32_t main() {
if(fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
cin.tie(0)->sync_with_stdio(0);
solve();
}
const int N=1e5+5;
const int B=300;
const int INF=1e9;
int n, m, q, ban[N], dp[N];
vector<int>adj[N];
vector<ii> largest[N];
void solve() {
cin>>n>>m>>q;
FOR(i,1,m){
int a,b; cin>>a>>b;
adj[b].eb(a);
}
FOR(i,1,n){
largest[i]={{-1,i}};
for(int j:adj[i]){
vector<ii>a=largest[j];
vector<ii>b(sz(a)+sz(largest[i]));
merge(all(a),all(largest[i]),b.begin(),greater<ii>());
b.erase(unique(all(b)), b.end());
while(sz(b)>B) b.pop_back();
largest[i]=b;
}
for(ii &j:largest[i]) ++j.fi;
}
memset(dp,-0x3f,sizeof(dp));
FOR(i,1,q){
int t,y; cin>>t>>y;
vector<int>c(y);
for(int &j:c) {
cin>>j;
ban[j]=true;
}
if(y<sz(largest[t])){
int mx=0;
for(ii j:largest[t]){
if(!ban[j.se]){
mx=max(mx,j.fi);
}
}
cout<<mx;
}
else{
for(int j:c) dp[j]=-INF;
FOR(j,1,t) if(!ban[j]) {
dp[j]=0;
for(int k:adj[j]) if(!ban[k]){
dp[j]=max(dp[j],dp[k])+1;
}
}
if(dp[t]<=-INF) cout<<-1;
else cout<<dp[t];
}
cout<<'\n';
for(int j:c) ban[j]=false;
}
}
