#include <bits/stdc++.h>
using namespace std;
double a,b,c,m;
int main(){
    cin>>a>>b>>c;
    double ab=a+b,bc=b+c;
    double max1=max(a,b,c),max2=max(ab,b,c),max3=max(a,b,bc);
    m=max1/(max2*max3);
    printf("%.3lf",m);
    return 0;
}