#include<iostream.h>
#include<string.h>
#include<fstream.h>
fstream f("litere.in",ios::in);
fstream g("litere.out",ios::out);

int N,k,ok,i,z;
char ch;
int Ap[133];
int main()
{
  f>>N;
  for(i=1;i<=N;i++)
  {
     f>>ch;
     Ap[ch]++;
  }

  return 0;
}