read carefully and write a C code for the following ARDUINO UNO:

there are 4 arduino uno push buttons and one servo motor being used and 4 push buttons are plugged into pin 6, pin7, pin 8 and pin 9. Write a program that the passcode is the following pin 8 pin 6 pin 7 and pin 9. When the buttons are pushed in the follwing order the servo motor should go from 180 degree to 0 degree. And when a wrong passcode is pressed the servo motor does nothing.

PLEASE MAKE COMMENTS AND ONLY C programming