Consider the following problem where the in put is an an array A [1...n]. Each entry could either be a number or a special symbol NULL. We want to output an array that is A but with all special symbols removed. For example, given the input [NULL, 2, 11, NULL, NULL, 3, 10, NULL, 11], the output should be [2, 11, 3, 10, 11]. Design an EREW PRAM algorithm that does this in O(logn) time using O(n) processors. Hint: This is a simple application of the parallel prefix algorithm. The algorithm should be fairly simple so do not overthink.