void *malloc(unsigned long);
int printf(char *, ...);
long atol(char *);
void exit(int);
int open(char *, int, int);
long read(int, void *, unsigned long);

void insertion_sort(int *a, long n)
{
	long i, j;
	for (i = 1; i < n; ++i) {
		for (j = i; j > 0; --j) {
			if (a[j] < a[j-1]) {
				int tmp = a[j];
				a[j] = a[j-1];
				a[j-1] = tmp;
			} else {
				break;
			}
		}
	}
}

void *read_arr(int fd, int *len)
{
	int size = 1024 * 1024 * 20;
	int i;
	char *arr = malloc(size);

	for (i = 0; ; ) {
		int rd = read(fd, arr + i, size - i);
		if (rd == -1)
			exit(2);
		if (rd == 0)
			break;
		i += rd;
	}
	printf("input is collected\n");
	*len = i;
	return arr;
}

int main(int argc, char **argv)
{
	int i, len;
	unsigned int sum = 0;
	int *arr;
	int fd;

	if (argc != 2) {
		printf("%d\n", argc);
		return 1;
	}

	len = atol(argv[1]);
	fd = open(argv[1], 0, 0);
	if (fd == -1)
		return 1;
	arr = read_arr(fd, &len);

	len /= 4;

	if (len != 64000)
		return 10;

	insertion_sort(arr, len);
	for (i = 0; i < len; ++i)
		sum = 2 * sum + arr[i];
	printf("%u\n", sum);
	return 0;
}