Substance A stored in the dark has no odor; however, when stored in light, it has a faint odor. When illuminated from A, a solid substance B and gas B is formed. Substance B is dissolved in a concentrated aqueous solution D, thus forming a solution D and gas E. Solution D again goes into solution D under the action of gas G with a sharp odor having acidic properties and formed by reaction of B with hydrogen. When mixing substance B with solution D, A is formed again, and when mixed with gas E and water, a solution containing G and Z is formed. Decipher substances A – Z and write the equation of all these reactions. (Olympics challenge)