Counter of two static switches with serial output.

I need to develop a project with STM32L010 and / or STM32L011 Microcontrollers. The project is as follows: I need a system in maximum energy saving with two fixed switches, that when they change each one from high to low they remain in deepsleep or standby (Lower energy consumption), when the two switches have changed each one from high to low, they must add a counter and store it in non-volatile memory, and send the accumulated counter data automatically every 12 hours via serial port. Note: These switches can independently remain high or low for minutes, hours, days, or weeks or months.