36 is related to 18 following certain logic. Following the same logic, 45 is related to 9. Which of the following number 56 is related to, following the same logic? (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g., 25- Operations on 25 such as adding /deleting /multiplying etc. to 25 can be performed. Breaking down 25 into 2 and 5 and then performing mathematical operations on 2 and 5 is not allowed)