#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>

void *
calloc (size_t bytes, size_t size)
{
	void *result;
	static int cnt;

	if (cnt++) {
		fprintf(stderr, "Been there, done that.\n");
		abort();
	}

	result = malloc(bytes);
	if (result)
	return memset(result, 0, bytes);
	return result;
}

int
main (int argc, char *argv[])
{

	if (argc != 2)
		return (1);

	size_t bytes = strtoul(argv[1], NULL, 10);

	return (calloc(bytes, 1) ? 42 : 0);
}