Suppose there is a X x Y x Z 3D matrix A of numbers having coordinates (i, j, k) where 0 ≤ i < X, 0 ≤ j < Y, 0 ≤ k < Z. Now another X x Y x Z matrix B is defined from A such that the (i, j, k) element of B is the sum of all the the numbers in A in the cuboid defined by the (0, 0, 0) and (i, j, k) elements as the diagonally opposite vertices. In other word (i, j, k) in B is the sum of numbers of A having coordinates (a, b, c) such that 0 ≤ a ≤ i, 0 ≤ b ≤ j, 0 ≤ c ≤ k. The problem is that given B, you have to find out A.