题解

#include<bits/stdc++.h>
using namespace std;
int main(){
    double s,t1,t2;
    cin>>s>>t1>>t2;
    double ball=s/t1*t2;
    double num=ball*3/4/3.14;
    double r=pow(num,1.0/3);
    cout<<fixed<<setprecision(2)<<r;
    return 0;
	}