#include <bits/stdc++.h>
#pragma GCC optimize ("O2,unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) {cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;}
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;
const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod=1000000007;
const int MAXN=100010, SQ=320;
int n, m, q, u, v, x, y, t, a, b, shit;
int dp[MAXN], mark[MAXN], sz[MAXN];
pii A[MAXN][SQ], B[2*SQ];
vector<int> G[MAXN];
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
cin>>n>>m>>q;
while (m--){
cin>>u>>v;
G[v].pb(u);
}
for (int v=1; v<=n; v++){
A[v][sz[v]++]={-1, v};
for (int u:G[v]){
shit++;
int t=sz[v]+sz[u];
merge(A[v], A[v]+sz[v], A[u], A[u]+sz[u], B, [](pii i, pii j){
return i.first>j.first;
});
sz[v]=0;
for (int i=0; i<t && sz[v]<SQ; i++) if (mark[B[i].second]!=shit){
mark[B[i].second]=shit;
A[v][sz[v]++]=B[i];
}
}
for (int i=0; i<sz[v]; i++) A[v][i].first++;
}
memset(mark, 0, sizeof(mark));
for (shit=1; shit<=q; shit++){
cin>>v>>t;
while (t--) cin>>x, mark[x]=shit;
bool ok=0;
for (int i=0; i<sz[v]; i++) if (mark[A[v][i].second]!=shit){
cout<<A[v][i].first<<"\n";
ok=1;
break ;
}
if (ok) continue ;
for (int i=1; i<=v; i++){
if (mark[i]==shit) dp[i]=-inf;
else dp[i]=0;
for (int u:G[i]) dp[i]=max(dp[i], dp[u]+1);
}
if (dp[v]<0) dp[v]=-1;
cout<<dp[v]<<"\n";
}
return 0;
}
