#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv)
{
	FILE *in1 = stdin;
	FILE *in2 = fdopen(3, "r");
	FILE *out = stdout;
	double m1, m2;
	if (argc == 1) {
		m1 = m2 = 0.5;
	} else if (argc == 3) {
		m1 = atof(argv[1]);
		m2 = atof(argv[2]);
		fprintf(stderr, "%f %f\n", m1, m2);
	} else {
		fprintf(stderr, "%s", "usage: rawadd [m1 m2] <in1 3<in2 >out\n");
		exit(1);
	}

	while (1) {
		int c;
		short v1, v2, vo;
		c = fgetc(in1);
		if (c == EOF) break;
		v1 = c;
		c = fgetc(in1);
		if (c == EOF) break;
		v1 = v1 + (c << 8);
		c = fgetc(in2);
		if (c == EOF) break;
		v2 = c;
		c = fgetc(in2);
		if (c == EOF) break;
		v2 = v2 + (c << 8);
		vo = (short)(((double)v1)*m1 + ((double)v2)*m2);
		fprintf(out, "%c%c", vo & 0xFF, (vo>>8) & 0xFF);
	}
	exit(0);
}