#include<bits/stdc++.h>
#define AC return 0
using namespace std;
void dfs(int a,int b,int c)
{
	double m=(max(a,b,c))/(max(a+b,b,c)*max(a,b,b+c))*1.0;
	cout<<fixed<<setprecision(3)<<m;
}
int main()
{
	int a,b,c;
	cin>>a>>b>>c;
	dfs(a,b,c);
	AC;    
}