For your reference only, here is a code for mergesort.

public class MergeSort$\{$

private static void merge$($Comparable$[]$ a$,$ Comparable$[]$ aux, int lo$,$ int mid, int hi$)$

$\{$

$$ for $($int k $=$ lo; k $<=$ hi; k$++)$ aux$[$k$]=$ a$[$k$]$;

$$ int i $=$ lo$,$ j $=$ mid$+1$;

$$ for $($int k $=$ lo; k $<=$ hi; k$++)$

$\{$

$$ if $($i $>$ mid$)$ a$[$k$]=$ aux$[$j$++]$;

$$ else if $($j $>$ hi$)$ a$[$k$]=$ aux$[$i$++]$;

$$ else if $($less$($aux$[$j$],$ aux$[$i$]))$ a$[$k$]=$ aux$[$j$++]$;

$$ else a$[$k$]=$ aux$[$i$++]$;

$\}$

$\}$

private static void sort$($Comparable$[]$ a$,$ Comparable$[]$ aux, int lo$,$ int hi$)\{$

$$ if $($hi $<=$ lo$)$ return;

$$ int mid $=$ lo $+($hi $-$ lo$)/2$;

$$ sort$($a$,$ aux, lo$,$ mid$)$;

$$ sort$($a$,$ aux, mid$+1,$ hi$)$;

$$ merge$($a$,$ aux, lo$,$ mid, hi$)$;

$/***$ array inspected here $***/$

$\}$

public static void sort$($Comparable$[]$ a$)$

$\{$

$$ Comparable$[]$ aux $=$ new Comparable$[$a$.$length$]$;

$$ sort$($a$,$ aux, $0,$ a$.$length $-1)$;

$\}$

$\}$

The input array is:

$01234567927860493730183$

At the end of a certain recursive call of method sort$(),$ line with $"/***...***/",$ the array looks like this:

$01234567496078923037318$

How many calls to method merge$()$ have been completed?