#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<string> v;
  string a;
  while (n--) {
    cin >> a;
    v.push_back(a);
  }
  int cot = 0;
  bool p = 1;
  int ans = 1000000;
  string c;
  for (int j = 0; j < v.size(); j++) {
    c = v[j];
    cot = 0;
    for (int i = 0; i < v.size(); i++) {
      if (c == v[i] || i == j)
        continue;
      else {
        int ncot = 0;
        string b = v[i];
        while (c != b) {
          ncot++;
          char d = b[0];
          b.erase(b.begin());
          b.push_back(d);
          if (ncot > b.length()) {
            p = 0;
            break;
          }
        }
        if (p == 0)
          break;
        else
          cot += ncot;
      }
    }
    if (p == 0) break;
    if (cot < ans) {
      ans = cot;
    }
  }
  if (p)
    cout << ans << endl;
  else
    cout << -1 << endl;
}
