program link;
  const
    max=10000;
  type
    sx=array[1..max]of string;
  var
    f1,f2:text;
    a:sx;
    n,ans:integer;
    procedure ini;
      var
        i:integer;
      begin
        assign(f1,'link.in');reset(f1);
        assign(f2,'link.out');rewrite(f2);
        readln(f1,n);
        for i:=1 to n do readln(f1,a[i]);
        close(f1);
        ans:=0;
      end;
    procedure try(k:integer;step:integer;s:string);
      var
        i,j:integer;
      begin
        for i:=k to n do begin
          j:=pos(s,a[i+1]);
          if j=1 then try(i+1,step+1,a[i+1]);
          if i=n then
            if step>ans then ans:=step;
        end;
      end;
  begin
    ini;
    try(1,1,a[1]);
    write(f2,ans);
    close(f2);
  end.