Write a program that switches on LED1 by pressing and holding S1, and off by releasing S1. Similarly, LED2 should switch on by pressing and holding S2, and off by releasing S2, i. e. they are ON only if the buttons are pressed. LED2 should change color each time S2 is pressed, i. e. if LED2 is red when S2 is pressed first, it should be, for example, green the next time S2 is pressed and blue for the time after that. This sequence may repeat itself.