What is the version of the following sentence with correct punctuation?

Q2 Instead of spending 54 days of praying can I choose to pray 15 decades of rosary for 18 days 9 days for petition and 9 days for thanksgiving
Q2. Instead of spending 54 days of praying, can I choose to pray 15 decades of rosary for 18 days (9 days for petition and 9 days for thanksgiving)?