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

struct test {
	char a1[0];
	char a2[0];
} __attribute__ ((__packed__));

int main(int argc, char **argv)
{
	struct test *test;
	int len1, len2;

	if (argc < 3)
		return 1;

	len1 = strlen(argv[1]) + 1;
	len2 = strlen(argv[2]) + 1;

	test = malloc(sizeof(*test) + len1 + len2);

#if 1
	strcpy(test->a1, argv[1]);
	strcpy(test->a2 + len1, argv[2]);
#else
	memcpy(test->a1, argv[1], len1);
	memcpy(test->a2 + len1, argv[2], len2);
#endif

	printf("%s:%s\n", test->a1, test->a2 + len1);

	return 0;
}