/* code by the cute PixelCat owo */
/* as cute as nyachoneko chan! */
//#pragma GCC optimize("O4,unroll-loops,no-stack-protector")
#include <bits/stdc++.h>
#define int ll //__int128
#define double long double
using namespace std;
using ll=long long;
using ull=unsigned long long;
using pii=pair<int,int>;
#define For(i,a,b) for(int i=a;i<=b;i++)
#define Fors(i,a,b,s) for(int i=a;i<=b;i+=s)
#define Forr(i,a,b) for(int i=a;i>=b;i--)
#define F first
#define S second
#define L(id) (id*2+1)
#define R(id) (id*2+2)
#define LO(x) (x&(-x))
#define eb emplace_back
#define all(x) x.begin(),x.end()
#define sz(x) ((int)x.size())
#define mkp make_pair
#define MOD (int)(1000000007)
#define INF (int)(1e17)
#define EPS (1e-6)
#ifdef NYAOWO
#define debug(...) do{\
cerr << __LINE__ <<\
" : ("#__VA_ARGS__ << ") = ";\
_OUT(__VA_ARGS__);\
cerr << flush;\
}while(0)
template<typename T> void _OUT(T _X) { cerr << _X << "\n"; }
template<typename T,typename...I>
void _OUT(T _X,I ...tail) { cerr << _X << ", "; _OUT(tail...); }
inline void USACO(const string &s) { cerr<<"USACO: "<<s<<"\n"; }
#else
#define debug(...)
inline void USACO(const string &s){
freopen((s+".in").c_str(),"r",stdin);
freopen((s+".out").c_str(),"w",stdout);
}
#endif
inline void NYA(){ ios::sync_with_stdio(false); cin.tie(0); }
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
inline int gcd(int a,int b) { return __gcd(a,b); }
inline int lcm(int a,int b) { return a/gcd(a,b)*b; }
int fpow(int b,int p,const int &mod){
int ans=1;
while(p){
if(p&1) ans=ans*b%mod;
p/=2; b=b*b%mod;
}
return ans;
}
int fpow(int b,int p) { return fpow(b,p,MOD); }
template<typename T> inline void chmin(T &_a,const T &_b) { if(_b<_a) _a=_b; }
template<typename T> inline void chmax(T &_a,const T &_b) { if(_b>_a) _a=_b; }
const int SQ=100;
vector<int> adj[100010];
int gg[100010];
int dp[100010];
int meow(int n){
For(i,1,n){
if(gg[i]) dp[i]=-INF;
else dp[i]=0;
for(auto &j:adj[i])
chmax(dp[i],dp[j]+1);
}
if(dp[n]<0) return -1;
return dp[n];
}
vector<pii> owo[100010]; //id,distance
void oao(int n){
For(i,1,n){
map<int,int> mp;
for(auto &j:adj[i])
for(auto &k:owo[j])
chmax(mp[k.F],k.S+1);
owo[i].eb(i,0);
for(auto &j:mp)
owo[i].push_back(j);
sort(all(owo[i]),[](pii a,pii b){
return a.S>b.S;
});
if(sz(owo[i])>SQ)
owo[i].erase(owo[i].begin()+SQ,owo[i].end());
}
}
int32_t main(){
NYA();
//nyaacho >/////<
int n,m; cin>>n>>m;
int q; cin>>q;
while(m--){
int a,b; cin>>a>>b;
adj[b].eb(a);
}
oao(n);
while(q--){
int t; cin>>t;
int ni; cin>>ni;
vector<int> v(ni);
for(auto &i:v){
cin>>i;
gg[i]=true;
}
if(ni>=SQ) cout<<meow(t)<<"\n";
else{
for(auto &i:owo[t]) if(!gg[i.F]){
cout<<i.S<<"\n";
goto NameSoHard;
}
cout<<"-1\n";
}
NameSoHard:;
for(auto &i:v)
gg[i]=false;
}
return 0;
}
