var n,i,j:byte;
    frecv:array[0..23] of 0..1;
    nr:longint;

begin
  readln(n);
  for i:=1 to n do
  begin
        readln (nr);
        frecv[nr mod 23]:=1;
  end;
  nr:=0;
  for i:=0 to 23 do
        if frecv[i]<>0 then
                inc(nr);
  write(nr);
end.