Assume that we want to apply mergesort to sort the array A with $5$ elements where the initial values of the array elements $($from

to

$)$ are A : $34021.$ How many times do we push an activation record $($for mergesort or merge$)$ onto the runtime stack before the completion of the algorithm? Note that mergesort$($A$,1,5)$ is the first activation record pushed onto the runtime stack. The mergesort algorithm here refers to the one taught in this class.