procedure work;

var

i,j,k,n:integer;

a:array[1..2000]of string;

s:string;

ans:array[1..2000]of integer;

max:integer;

begin

readln(n);

for i:=1 to n do begin readln(a[i]);ans[i]:=1;end;

for i:=1 to n do

for j:=i+1 to n do

begin

s:=copy(a[j],1,length(a[i]));

if (s=a[i])and(ans[i]+1>ans[j])then ans[j]:=ans[i]+1;

end;

max:=0;

for i:=1 to n do

if ans[i]>max then max:=ans[i];

writeln(max);

end;

begin

work;

end.