discrete math $2$ question

Describe the worst$-$case time complexity, measured in terms of comparisons, for this following

algorithm that locates an element in a list of increasing integers by successively splitting the list into four

sublists of equal $($or as close to equal as possible$)$ size, and restricting the search to the appropriate piece.

Procedure $4-$ary search $\{\begin{array}{c}x\end{array}$ : integer, $a_1,a_2,$dots,$a_n$ : increasing integers