Prove that it is possible to place 2n(2n+1) parallelepipedic (rectangular) pieces of soap of dimensions 1×2×(n+1) in a cubic box with edge 2n+1 if and only if n is even or n=1.Remark. It is assumed that the edges of the pieces of soap are parallel to the edges of the box. geometry3D geometrycombinatoricspackingIMO Shortlist