#include <bits/stdc++.h>
using namespace std;

int main(){
  int n; cin >> n;
  map<int, int> m;
  for (int i = 0; i < n; i++) {
    string s; cin >> s;
    m[s.size()]++;
  }
  int ma = 0; int ans;
  for (auto it = m.begin(); it != m.end(); it++) {
    if (it->second >= ma) {
      ans = it -> first;
      ma = it->second;
    }
  }
  cout << ans - 2 << endl;
  return 0;
}