We know that, using Karatsuba algorithm, it takes worst time complexity

$O(n^{1\mathrm{.}59})$ to multiply two bit strings with length $n.$ Suppose that I want to

multiply $n$ bit strings ${}_1,$cdots,${}_n,$ each of which is with length $n.$ I do this

by the following naiveKaratsuba algorithm:

$={}_1$;

For $i=2ton$

$,=*{}_i(using$ Karatsuba$)$;

return $.$

Compute the worst$-$case complexity of naiveKaratsuba.