#include <bits/stdc++.h>
/*#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")*/
#pragma GCC optimize("O2")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,sse,sse2,fma")
using namespace std;
using ll = /*long long*/ int;
#define F first
#define S second
#define pb push_back
#define lc v<<1
#define rc 1+(v<<1)
#define fast_io ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
const int N=1e5+10,LN=20,M=1e5+10,SQ=200,inf=1e9;
const ll INF=1e18;
const int MOD=1000000007 /*998244353*/;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using pll=pair<ll,ll>;
using pii=pair<int,int>;
#define ordered_set tree<pll, null_type,less<pll>, rb_tree_tag,tree_order_statistics_node_update>
ll pow(ll x, ll y, ll mod){
ll ans=1;
while (y != 0) {
if (y & 1) ans = ans * x % mod;
y >>= 1;
x = x * x % mod;
}
return ans;
}
ll n,m,q;
bool g[N];
vector<pll> d[N];
vector<ll> adj[N];
int main(){
fast_io;
cin >> n >> m >> q;
for(ll i=1; i<=m; i++){
ll v,u;
cin >> v >> u;
adj[u].pb(v);
}
for(ll i=1; i<=n; i++){
d[i].pb({0,i});
ll k=1;
for(ll j : adj[i]){
for(pll p : d[j])
d[i].pb({p.F-1,p.S});
inplace_merge(d[i].begin(),d[i].begin()+k,d[i].end());
vector<pll> v;
for(pll p : d[i]) if(!g[p.S]) v.pb(p),g[p.S]=1;
for(pll p : v) g[p.S]=0;
swap(v,d[i]);
k=d[i].size();
k=min(k,SQ);
d[i].resize(k);
}
}
for(ll i=1; i<=n; i++) d[i].pb({1,0});
while(q--){
ll v,k;
set<ll> t;
cin >> v >> k;
for(ll i=0; i<k; i++){
ll u;
cin >> u;
t.insert(u);
}
if(k<SQ){
for(pll p : d[v]){
if(t.find(p.S)==t.end()){
cout << -p.F << '\n';
break;
}
}
}else{
ll f[N];
for(ll i=1; i<=n; i++){
if(t.find(i)==t.end()){
f[i]=0;
}else f[i]=-1;
for(ll j : adj[i]) if(f[j]!=-1) f[i]=max(f[i],f[j]+1);
}
cout << f[v] << '\n';
}
}
return 0;
}
