Final answer:
The question seems to ask for the decoding of a cryptogram using a numerical key, but the information provided lacks sufficient clarity to perform a definitive decoding.
Step-by-step explanation:
The student's question seems to involve using a cryptogram and specific numerical values to decode a message. A cryptogram is a type of puzzle that uses a substitution cipher where each letter in the alphabet is replaced by a code made of numbers, symbols, or another set of letters. Decoding the message involves understanding the key to the cipher, which in this case could be the sequence 'a = 1 2 2 3 7 9 -2 -4 -3' and transforming the numbers back into letters to make a readable sentence or phrase.
To decode the message, you need to apply the key correctly. Unfortunately, the information given in the question is a bit fragmented and doesn't provide a clear sequence or rule for decoding beyond the initial series of numbers associated with 'a'. Without additional context or clarification on what 'a-1' means as an instruction or what the series of numbers provided correspond to (letters, word shifts, etc), it is not possible to provide a correct and definitive answer.