program ex;
type
 ss=array[1..10000]of string;
 sz=array[1..10000]of boolean;
var
 a:ss;
 b:sz;
 f1,f2:text;
 n,tot:integer;
procedure init;
 var
  i:integer;
 begin
  assign(f1,'link.in');
  assign(f2,'link.out');
  reset(f1);
  rewrite(f2);
  readln(f1,n);
  for i:=1 to n do
   readln(f1,a[i]);
  close(f1);
  for i:=1 to n do
   b[i]:=true;
 end;
procedure try(s:string;t:integer);
 var
  i,j:integer;
  s1:string;
 begin
  if t>tot then tot:=t;
  for i:=1 to n do
   if (pos(s,a[i])<>0)and(b[i]=true) then
    begin
     inc(t);
     s1:=a[i];
     b[i]:=false;
     try(s1,t);
     dec(t);
     b[i]:=true;
    end;
 end;
begin
 init;
 try(a[1],0);
 writeln(f2,tot);
 close(f2);
end.