#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
int main(){
    double a,b,c,d,e,f;cin>>a>>b>>c>>d>>e>>f;
    cout << fixed << setprecision(10) << sqrt((f-e)/a + (c*c)/(4*a*a) + (d*d)/(4*a*a)) << endl;
    //double A = a;
    //double B = b;
    //double aa = -c/(2*A);
    //double bb = -d/(2*B);
    //double r2 = aa*aa+bb*bb-(e-f);
    //cout << fixed << setprecision(10) << sqrt(r2) << endl;
}