#include <bits/stdc++.h> using namespace std; int maxn(int a,int b,int c){return max(max(a,b),max(a,c));} int main(){ int a,b,c; cin>>a>>b>>c; printf("%.2lf",maxn(a,b,c)/(maxn(a+b,b,c)*maxn(a,b,b+c)*1.0)); }