#include <stdio.h>

void print_binary(unsigned int number)
{
    if (number >> 1) {
        print_binary(number >> 1);
    }
    putc((number & 1) ? '1' : '0', stdout);
}

int main(void) {
	print_binary(42);
	printf("\n");
	print_binary(0);
	printf("\n");
	print_binary(-12);
	printf("\n");
	return 0;
}