Six cube Instant Insanity

This puzzle is a modification of the famous cube-stacking puzzle Instant Insanity. Stack the six cubes so that all six symbols (circle, square, heart, plus, triangle, and star) are visible on the four sides of the stack. This set of cubes was introduced by T. A. Brown in 1968 in his article "A Note on 'Instant Insanity.'" Unlike Instant Insanity, which has a unique solution, this puzzle has three solutions. (Because every symbol appears on every cube, the existence of one solution implies the existence of three solutions—exercise for the reader!)