//DUEL
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define x first
#define y second
#define pii pair<int,int>
#define pb push_back
#define eb emplace_back
#pragma GCC optimize("unroll-loops")
#define shandom_ruffle(a, b) shuffle(a, b, rng)
#define vi vector<int>
#define vl vector<ll>
#define popcnt __builtin_popcount
#define popcntll __builtin_popcountll
#define all(a) begin(a),end(a)
using namespace std;
using namespace __gnu_pbds;
using ll=long long;
using ull=unsigned long long;
using ld=long double;
int MOD=1000000007;
int MOD2=998244353;
vector<int> bases;
const ll LLINF=1ll<<60;
const char en='\n';
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void yes() {cout<<"YES"<<en; exit(0);}
void no() {cout<<"NO"<<en; exit(0);}
inline int rund() {int x576363482791fuweh=rng();return abs(x576363482791fuweh)%RAND_MAX;}
template<class T>
void prVec(vector<T> w,bool fl=false)
{
cout<<w.size()<<en;
for (int i=0;i<int(w.size())-1;++i) cout<<w[i]<<' ';
if (w.size()) cout<<w[w.size()-1]<<en;
if (fl) cout<<flush;
}
void M998()
{
swap(MOD,MOD2);
}
ll raand()
{
ll a=rund();
a*=RAND_MAX;
a+=rund();
return a;
}
#define rand raand
ll raaand()
{
return raand()*(MOD-7)+raand();
}
string to_upper(string a)
{
for (int i=0;i<(int)a.size();++i) if (a[i]>='a' && a[i]<='z') a[i]-='a'-'A';
return a;
}
string to_lower(string a)
{
for (int i=0;i<(int)a.size();++i) if (a[i]>='A' && a[i]<='Z') a[i]+='a'-'A';
return a;
}
ll sti(string a,int base=10)
{
ll k=0;
for (int i=0;i<(int)a.size();++i)
{
k*=base;
k+=a[i]-'0';
}
return k;
}
template<class T>
void eras(vector<T>& a,T b)
{
a.erase(find(a.begin(),a.end(),b));
}
string its(ll k,int base=10)
{
if (k==0) return "0";
string a;
while (k)
{
a.push_back((k%base)+'0');
k/=base;
}
reverse(a.begin(),a.end());
return a;
}
ll min(ll a,int b)
{
if (a<b) return a;
return b;
}
ll min(int a,ll b)
{
if (a<b) return a;
return b;
}
ll max(ll a,int b)
{
if (a>b) return a;
return b;
}
ll max(int a,ll b)
{
if (a>b) return a;
return b;
}
ll gcd(ll a,ll b)
{
if (b==0) return a;
return gcd(b,a%b);
}
ll lcm(ll a,ll b)
{
return a/gcd(a,b)*b;
}
template<class T,class K>
pair<T,K> mp(T a,K b)
{
return make_pair(a,b);
}
inline int mult(ll a,ll b)
{
return (a*b)%MOD;
}
inline int pot(int n,int k)
{
if (k==0) return 1;
ll a=pot(n,k/2);
a=mult(a,a);
if (k%2) return mult(a,n);
else return a;
}
int divide(int a,int b)
{
return mult(a,pot(b,MOD-2));
}
inline int sub(int a,int b)
{
if (a-b>=0) return a-b;
return a-b+MOD;
}
inline int add(int a,int b)
{
if (a+b>=MOD) return a+b-MOD;
return a+b;
}
bool prime(ll a)
{
if (a==1) return 0;
for (int i=2;i<=round(sqrt(a));++i)
{
if (a%i==0) return 0;
}
return 1;
}
const int N=100010,M=1<<17,C=100;
int n,m,q,dp[N];
vi ord,ch[N];
ll re[N][C+10];
int id[N],sz[N];
bool bio[N];
vi sta;
void mer(int i,int j)
{
int cn=0,a=0,b=0;
while (a+b!=sz[i]+sz[j] && cn<C)
{
if (a==sz[i])
{
if (!bio[re[j][b]%M]) re[N-1][cn++]=re[j][b]+M,bio[re[j][b]%M]=1;
++b;
continue;
}
if (b==sz[j])
{
if (!bio[re[i][a]%M]) re[N-1][cn++]=re[i][a],bio[re[i][a]%M]=1;
++a;
continue;
}
if (re[i][a]>re[j][b]+M)
{
if (!bio[re[i][a]%M]) re[N-1][cn++]=re[i][a],bio[re[i][a]%M]=1;
++a;
continue;
}
if (!bio[re[j][b]%M]) re[N-1][cn++]=re[j][b]+M,bio[re[j][b]%M]=1;
++b;
}
sz[i]=cn;
for (int u=0;u<cn;++u) re[i][u]=re[N-1][u],bio[re[N-1][u]%M]=0;
}
void dfs(int i)
{
if (id[i]) return;
--id[i];
ord.pb(i);
for (auto a: ch[i])
{
--id[a];
dfs(a);
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
for (int i=0;i<10;++i) bases.push_back(rand()%(MOD-13893829*2)+13893829);
cin>>n>>m>>q;
for (int i=0;i<m;++i)
{
int a,b;
cin>>b>>a;
ch[a].pb(b);
++id[b];
}
for (int i=1;i<=n;++i) dfs(i),sz[i]=1,re[i][0]=i;
reverse(all(ord));
for (auto a: ord) for (auto b: ch[a]) mer(a,b);
/*for (int i=1;i<=n;++i)
{
cout<<sz[i]<<en;
for (int j=0;j<sz[i];++j) cout<<re[i][j]%M<<' '<<re[i][j]/M<<en;
cout<<en;
}*/
while (q--)
{
int cn,i;
vi v;
cin>>i>>cn;
while (cn--)
{
int x;
cin>>x;
v.pb(x);
bio[x]=1;
}
bool don=0;
for (int u=0;u<sz[i];++u) if (!bio[re[i][u]%M])
{
cout<<re[i][u]/M<<en;
for (auto a: v) bio[a]=0;
don=1;
break;
}
if (don) continue;
if (sz[i]<C)
{
cout<<-1<<en;
for (auto a: v) bio[a]=0;
continue;
}
memset(dp,0,sizeof(dp));
for (auto a: v) dp[a]=-MOD;
for (auto a: ord) for (auto b: ch[a]) dp[a]=max(dp[a],dp[b]+1);
for (auto a: v) bio[a]=0;
if (dp[i]>=0) cout<<dp[i]<<en;
else cout<<-1<<en;
}
}
