Compute f(x,n)

Problem Background

Special for beginners, ^_^

Problem Description

Given

$$f(x,n)={x\over{n+{x\over{(n-1)+{x\over{(n-2)+\dots _{x\over 1+x}}}}}}}$$

Given the values of $x$ and $n$, use a recursive function to compute $f(x,n)$.

Input Format

The first number is the value of $x$, the second is the value of $n$.

Output Format

Output the value of $f(x,n)$, formatted to two decimal places (e.g. 0.40).

Sample Input

1 2

Sample Output

0.40

Constraints

Time limit: 1s, memory limit: 1024KiB for each test case.