#include<bits/stdc++.h>
using namespace std;
int main(){
    int p,q,r;
    cin >> p >> q >> r;
    double a[6];
    a[0] = (double)p/(double)(p+q+r);
    a[1] = (double)q/(double)(p+q+r);
    a[2] = (double)r/(double)(p+q+r);
    a[3] = 1.0-a[0];
    a[4] = 1.0-a[1];
    a[5] = 1.0-a[2];
    double ans = a[0];
    for(int i=1;i<=5;i++){
        ans = max(ans,a[i]);
    }
   printf("%.10lf",ans);
    
}