#include <stdio.h>
#include <math.h>
int main () 
{
double a,b,c,s,area;
scanf("%lf,%lf,%lf",&a,&b,&c);
s=(a+b+c)/2;
area=sqrt(s*(s-a)*(s-b)*(s-c));
printf("a=%f\tb=%f\tc=%f\n",a,b,c);
printf("area=%f\n",area);
	return 0;
}