/* (c) kreator, 2000AD
 * rijec je o CCITT CRC 16 */

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

#define POLY 0xa001 /* 0x8408 /* 0x1021 */
void crc16(unsigned data, unsigned *crc)
{
	int i;
	for (i=0; i<8; ++i)
	{
		if ((*crc & 0x0001) ^ (data & 0x0001))
			*crc=(*crc >> 1) ^ POLY;
		else *crc>>=1;
		data>>=1;
	}
}

void crc16string(char *string, unsigned *crc)
{
	char *stringptr=string;
	do crc16(*stringptr, crc); while (*(++stringptr));
}

int main(void)
{
	char stringy[255];
	unsigned int crc=0;
	fgets(stringy, 254, stdin);
	crc16string(stringy, &crc);
	fprintf(stdout, "string=%s crc=%u\n", stringy, crc);
	return EXIT_SUCCESS;
}