原题链接--

https://acs.jxnu.edu.cn/problem/CF5Dhttps://acs.jxnu.edu.cn/problem/CF5D

Follow Traffic Rules

 1000ms  65536K

描述：

Everybody knows that the capital of Berland is connected to Bercouver (the Olympic capital) by a direct road. To improve the road's traffic capacity, there was placed just one traffic sign, limiting the maximum speed. Traffic signs in Berland are a bit peculiar, because they limit the speed only at that point on the road where they are placed. Right after passing the sign it is allowed to drive at any speed.

It is known that the car of an average Berland citizen has the acceleration (deceleration) speed of a km/h2, and has maximum speed of v km/h. The road has the length of l km, and the speed sign, limiting the speed to w km/h, is placed d km (1 ≤ d < l) away from the capital of Berland. The car has a zero speed at the beginning of the journey. Find the minimum time that an average Berland citizen will need to get from the capital to Bercouver, if he drives at the optimal speed.

The car can enter Bercouver at any speed.

译文：每个人都知道伯兰的首都与贝尔科夫（奥林匹克之都）由一条直接的路相连接。为提高道路的通行能力，只放置了一个交通标志，来限制最大速度。伯兰的交通标志有点特别，因为仅在他们放置标志的那一点限速。在通过标志后，就可以以任何速度行驶。

众所周知在伯兰的居民平均行驶的汽车加速（减数）度为a km/h2,并且有最大速度v km/h。路长l km,速度标志的限速为w km/h,放置地离伯兰首都d km (1 ≤ d < l)远。在旅途开始时汽车的速度为0。找出平均一个伯兰的居民从伯兰的首都行驶到贝尔科夫所用的最少时间，如果他按最佳速度来行驶。

汽车可以按任意速度到达贝尔科夫。

输入：

The first line of the input file contains two integer numbers a and v (1 ≤ a, v ≤ 10000). The second line contains three integer numbers l, d and w (2 ≤ l ≤ 10000; 1 ≤ d < l; 1 ≤ w ≤ 10000).

译文：第一行输入文件包含两个整数a和v (1 ≤ a, v ≤ 10000)。第二行包含三个整数l, d和w (2 ≤ l ≤ 10000; 1 ≤ d < l; 1 ≤ w ≤ 10000)。

输出：

Print the answer with at least five digits after the decimal point.

译文：打印的答案至少保留到小数点后5位。

样例输入：

1 1
2 1 3

样例输出：

2.500000000000

样例输入：

5 70
200 170 40

样例输出：

8.965874696353