Let's Construct! - ②

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Time limit1sMemory limit512 MB

Summary

Given side lengths c of AB and b of AC, compute the ratio in which the internal angle bisector of angle A divides side BC.

Level: Easy3 of 10
Topics: Math, Geometry, Implementation
Solved: No attempts yet

Problem

Jaewon, the king of geometric construction, came home after playing outside with great excitement, and since he had nothing to do, he decided to do some construction. Jaewon first drew triangle ABC on a piece of paper. Then he marked M as the intersection of the angle bisector of angle BAC and side BC.

Given the length $c$ of side AB and the length $b$ of side AC, write a program that computes the value of (length of segment BM) ÷ (length of segment CM).

Input

The first line gives the values of $c$ and $b$ in that order, separated by a single space. (The values of $c$ and $b$ are positive integers no greater than 1,000,000,000.)

Output

Print the answer required by the problem on the first line. An absolute or relative error of up to $10^{-6}$ is allowed.

Examples2

Example 1
Input
```
9 3
```
Expected output
```
3
```
Example 2
Input
```
15 7
```
Expected output
```
2.1428571428
```