#include <bits/stdc++.h>
using namespace std;
#define int long long
#define double long double
#define FOR(i,l,r,d) for(int i=(l);i<=(r);i+=(d))
#define vi vector<int>
#define pii pair<int,int>
#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define mkp make_pair
const int INF=2147483647;
const int MOD=1000000007;
const int mod=998244353;
const double eps=1e-12;
int n,m,q;
int B;
vi edge[100001];
int dp[100001][320];
int st[100001][320];
bool valid[100001];
bool used[100001];
int dp2[100001];
void DP(int from,int to){
int tmp_dp[320];
int tmp_st[320];
int cnt=0;
int L=0, R=0;
while(cnt<B and (L<B or R<B)){
int D,S;
if( R==B or ( L<B and dp[from][L]+1 > dp[to][R] ) ){
D = dp[from][L] + 1;
S = st[from][L];
L++;
}
else{
D = dp[to][R];
S = st[to][R];
R++;
}
if( used[S] == 0 ){
tmp_dp[cnt] = D;
tmp_st[cnt] = S;
used[S] = 1;
cnt++;
}
}
FOR(i,0,cnt-1,1){
dp[to][i] = tmp_dp[i];
st[to][i] = tmp_st[i];
used[ tmp_st[i] ] = 0;
}
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin>>n>>m>>q;
int v1,v2;
FOR(i,0,m-1,1){
cin>>v1>>v2;
v1--;
v2--;
edge[v1].pb(v2);
}
/// block size
B = floor(sqrt(n)+eps);
/// initialize dp
FOR(i,0,n-1,1){
dp[i][0] = 0;
st[i][0] = i;
FOR(j,1,B-1,1){
dp[i][j] = -INF;
st[i][j] = n;
}
}
/// dp
FOR(i,0,n-1,1){
for(int j : edge[i]){
//cerr<<"DP("<<i<<","<<j<<")"<<endl;
DP(i,j);
}
}
/// valid[]
FOR(i,0,n-1,1){
valid[i] = 1;
}
while(q--){
int qidx;
int invsz;
vi inv;
cin>>qidx>>invsz;
qidx--;
inv.clear();
FOR(i,0,invsz-1,1){
cin>>v1;
v1--;
inv.pb(v1);
valid[v1] = 0;
}
if( invsz >= B ){
//cerr<<"invsz >= B"<<endl;
/// initialize dp2
FOR(i,0,n-1,1){
if( valid[i] == 0 ){
dp2[i] = -INF;
}
else{
dp2[i] = 0;
}
}
/// dp2
FOR(i,0,n-1,1){
for(int j : edge[i]){
dp2[j] = max( dp2[j] , dp2[i]+1 );
}
}
if( dp2[qidx] >= 0 ){
cout<<dp2[qidx]<<'\n';
}
else{
cout<<-1<<'\n';
}
}
else{
//cerr<<"invsz < B"<<endl;
int ptr=0;
while( valid[ st[qidx][ptr] ]==0 and dp[qidx][ptr]>=0 ){
ptr++;
}
if( dp[qidx][ptr] >= 0 ){
cout<<dp[qidx][ptr]<<'\n';
}
else{
cout<<-1<<'\n';
}
/*
FOR(i,0,B-1,1){
cerr<<dp[qidx][i]<<" ";
}
cerr<<endl;
FOR(i,0,B-1,1){
cerr<<st[qidx][i]<<" ";
}
cerr<<endl;
FOR(i,0,B-1,1){
cerr<<valid[ st[qidx][i] ]<<" ";
}
cerr<<endl;
*/
}
for(int i : inv){
valid[i] = 1;
}
}
return 0;
}
