题解 | #游游开车出游#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        double v = in.nextDouble();
        double x = in.nextDouble();
        double y = in.nextDouble();

	  // 数学问题，直接求解，注意加油时间最小为0
        double t = Math.sqrt(y / x) - v / x;
        t = Math.max(t, 0);
        v = getV(v, t, x);
        System.out.println(y / v + t);
    }

    public static double getV(double v, double t, double x) {
        return v + t * x;
    }
}