#include <cmath>
#include <iomanip>
#include <iostream>
using namespace std;
int main() {
    double a, b, c, d, e, f; cin >> a >> b >> c >> d >> e >> f;
    cout << setprecision(16)
         << sqrt((f - e) / a + pow(c / a / 2, 2) + pow(d / a / 2, 2)) << endl;
}