#include <stdio.h>

unsigned PORTA = 0;

#define OUTPUT PORTA
#define BIT(n) (1 << n)
#define LED(op) (OUTPUT op BIT(4))
#define ON |=
#define OFF &=~

int main(void) {
	printf("PORTA = %u\n", PORTA);
	LED(ON);
	printf("PORTA = %u\n", PORTA);
	LED(OFF);
	printf("PORTA = %u\n", PORTA);
	return 0;
}