#include <stdio.h>

extern int __bss_start, _end;
int a, b, c, d;  /* un-initialized */

int main()
{
	int *ptr;
	a = 1, b = 2, c = 3, d = 4;

	for (ptr = &__bss_start; ptr != &_end; ptr++) {
		printf("%d\n", *ptr);
	}
	return 0;
}