Problem Background

Rana: Lamp, listen to me.

Rana: Washing machines are so interesting.

Lamp: Huh... washing machines...?

Rana: Clothes keep spinning around, it's fascinating to observe.

Rana: Lamp, you should try it too.

Lamp: Huh...? Okay...!

"It's so interesting to see them spin around!"

Problem Description

Rana and Tomorin are observing clothes in a washing machine and notice that the clothes are undergoing uniform circular motion. They know the initial position of the clothes, the observation time, and the rotational speed of the washing machine. They hope you can help them calculate the displacement length from the initial position to the position at the end of the observation. The clothes can be considered as a point mass.

Input Format

The input consists of three lines.

The first line contains two integers $x, y$ ($-1000 \leq x, y \leq 1000$), representing the initial position of the clothes in a Cartesian coordinate system with the center of the washing machine as the origin, in units of length.

The second line contains a real number $t$ ($0 \leq t \leq 100$), representing the observation time, in units of time.

The third line contains a real number $v$ ($0 \leq v \leq 100$), representing the rotational speed of the washing machine, in revolutions per unit time.

Output Format

The output consists of a single line.

Output a real number representing the answer. Answers that have an absolute or relative error not exceeding $10^{-6}$ from the standard answer are considered correct.

Sample Input and Output

Sample Input #1

-1 0
11
0.5

Sample Output #1

2.0000000000

Sample Input #2

-1 0
10
0.5

Sample Output #2

0.0000000000

见题面 Input 部分

见题面 Output 部分