#include <avr/io.h>

int main ()
{
	unsigned char z;

	DDRB = 0;
	DDRD = 0xFF;

	while(1)
	{
		z = PINB;	
		z = z & 0b00000011; 

		switch(z)
		{
			case 0: PORTD = '0'; break; 
			case 1: PORTD = '1'; break; 
			case 2: PORTD = '2'; break; 
			case 3: PORTD = '3'; break; 
		}
	}

	return 0;
}