#include <bits/stdc++.h>
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef long double ld;

vector<int> g[10101];
int u[10101];
ll d[10101];

int n;

ll test(int x) {
  queue<int> bfs;
  for (int i = 1; i <= n; i++) {
    u[i] = 0;
    d[i] = 0;
  }
  bfs.push(x);
  u[x] = 1;
  d[x] = 1;
  while (!bfs.empty()) {
    int t = bfs.front();
    bfs.pop();
    for (int nx : g[t]) {
      if (u[nx] == 0) {
        u[nx] = 1;
        d[nx] = d[t] + 1;
        bfs.push(nx);
      }
    }
  }
  ll v = 0;
  for (int i = 1; i <= n; i++) {
    if (u[i] == 0) {
      return -1;
    } else {
      v += d[i];
    }
  }
  return v;
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  assert(n >= 1 && n <= 5000);
  int m = 0;
  for (int i = 1; i <= n; i++) {
    int k;
    cin >> k;
    m += k;
    for (int j = 0; j < k; j++) {
      int a;
      cin >> a;
      assert(a >= 1 && a <= n && a != i);
      g[a].push_back(i);
    }
  }
  assert(m >= 1 && m <= 10000);
  ll v = -1;
  for (int i = 1; i <= n; i++) {
    ll asd = test(i);
    if (asd != -1) {
      if (v == -1) v = asd;
      else v = min(v, asd);
    }
  }
  cout << v << endl;
}