(2E)-N'-{(2E)-1-[1-cyclohexyl-2,4,6-trioxo-5-(prop-2-en-1-yl)hexahydropyrimidin-5-yl]propan-2-ylidene}-2-{1-[1-cyclohexyl-2,4,6-trioxo-5-(prop-2-en-1-yl)hexahydropyrimidin-5-yl]propan-2-ylidene}hydrazinecarbohydrazonamide