#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define all(x) x.begin() , x.end()
#define file_init freopen("input.txt", "r+", stdin); freopen("output.txt", "w+", stdout);
#define random_init mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
#define int long long
#define pb push_back
#define pii pair<int,int>
#define F first
#define S second
const int maxn=1e4,INF=1e18;
int dis[maxn],mark[maxn],cntd[maxn];
vector<int> m[maxn];
inline int BFS(int u,int n){
queue<int> q;
q.push(u);
mark[u]=1;
dis[u]=1;
cntd[dis[u]]=1;
int mx=0;
// cout<<"####"<<u<<"####"<<'\n';
while(q.size()){
u=q.front();
for(int v : m[u]){
if(!mark[v]){
dis[v]=dis[u]+1;
cntd[dis[v]]++;
mark[v]=1;
q.push(v);
}
}
mx=dis[u];
q.pop();
}
int ans=0,sum=0;
for(int i=mx;i>0;i--){
sum+=cntd[i];
ans+=sum;
// cout<<i<<" "<<cntd[i]<<'\n';
}
int cnt=0;
for(int i=0;i<=n;i++){
if(mark[i]) cnt++;
dis[i]=cntd[i]=mark[i]=0;
}
if(cnt<n) return -1;
return ans;
}
int mk[maxn];
void DFS(int u){
mk[u]=1;
for(int v : m[u]){
if(!mk[v]) DFS(v);
}
}
int32_t main(){
ios_base::sync_with_stdio(0);
int n;
cin>>n;
for(int i=1;i<=n;i++){
int k; cin>>k;
for(int j=0;j<k;j++){
int x; cin>>x;
m[x].pb(i);
}
}
int ans=INF;
for(int i=1;i<=n;i++){
int x=BFS(i,n);
if(x!=-1)
ans=min(ans,x);
}
cout<<(ans==INF ? -1 : ans);
return 0;
}
