#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  Int n;
  cin>>n;
  vector<Int> cnt(1020);
  for(Int i=0;i<n;i++){
    string s;
    cin>>s;
    cnt[s.size()]++;
  }
  Int ans=0;
  for(Int i=0;i<1020;i++)
    if(cnt[ans]<=cnt[i]) ans=i;
  cout<<ans-2<<endl;
  return 0;
}