I WILL GIVE DISLIKES $!!!$ IF ANYTHING WRONG HAPPENS IN MY QUESTION, BETTER SKIP IT$!!!$

$"$;

$$ s $$

$.$

XB$10$

s$.$push$()$

$1.$

$.()$

$1.$

$2.$

$3..->->$

$().$ i$-$th $$ k $$ i$-$th $2($k $-1)?$

$()$ i$-$th $$ k $"$