#include <bits/stdc++.h>
using namespace std;
double a,b,c,ans;
double maxx(double a,double b,double c){
	if(a>b && a>c) return a;
	else if(b>a && b>c) return b;
	else if(c>a && c>b) return c;
	else return a;
}
int main()
{
	scanf("%lf %lf %lf",&a,&b,&c);
	ans=maxx(a,b,c)/(maxx(a+b,b,c)*maxx(a,b,b+c));
	printf("%.3f",ans); 
	return 0;
}