#include<stdio.h>
#include<math.h>
int a,b,c;
double max(double a,double b,double c)
{
	if(a>=b&&a>=c)
	return a;
	if(b>c&&b>a)
	return b;
	if(c>a&&c>b)
	return c;
}
int main()
{
	double m;
	scanf("%d%d%d",&a,&b,&c);
	if(fabs(a)<=50&&fabs(b)<=50&&fabs(c)<=50)
	m=max(a,b,c)/(max(a+b,b,c)*max(a,b,b+c));
	printf("%.3lf",m);
	return 0;
}