#include<bits/stdc++.h>
using namespace std;
int maxhy(int x,int y,int z){
		if(x>=y&&y>=z||x>=z&&z>=y)return x;
		if(y>=x&&x>=z||y>=z&&z>=x)return y;
		if(z>=y&&y>=x||z>=x&&x>=y)return z; 
	}
	int main(){
		double m;
		int a,b,c;
		cin>>a>>b>>c;
		double laoliu=maxhy(a+b,b,c)*maxhy(a,b,b+c);
		m=maxhy(a,b,c)/laoliu;
		cout<<fixed<<setprecision(3)<<m;
	return 0;
}