program link(input,output);
var
 sta:array[1..10000]of string;
 top,i,n,max:integer;
 st:string;
procedure push(st:string);
begin
 inc(top);
 sta[top]:=st;
end;
procedure pop;
begin
 dec(top);
end;
begin
 assign(input,'link.in');assign(output,'link.out');
 reset(input);rewrite(output);
 readln(n);
 top:=0; max:=0;
 readln(st);
 push(st);
 for i:=2 to n do begin
  readln(st);
  if pos(sta[top],st)<>0 then push(st)
  else begin
   if top>max then max:=top;
   repeat
    pop;
   until pos(sta[top],st)<>0;
   push(st);
  end;
 end;
 write(max);
 close(input);close(output);
end.