Arduino code modification

We have an Arduino script. This script executes a function. We want this code to be modified to allow the following: The MCU goes into Deep Sleep mode. It responds to a UART command, wakes up, executes the function, transmits the result and returns to Deep Sleep mode. So, • Deep sleep mode must be integrated with its library. • An interrupt must be configured on the PB11 input. • The interrupt must release the MCU from the deep sleep mode. • The MCU must perform the function • The MCU transmits the result via TX3 (pin PB10)