**Time limit:**0.50 s**Memory limit:**512 MB

Maija picks one number from $E$ uniformly at random. What is the probability that the first digit of the number is $a$ when the number is written in base $b$?

**Input**

The only input line contains two integers $a$ and $b$.

**Output**

Print one line that contains the probability. The difference between your answer and the correct answer has to be less than $10^{-6}$.

**Constraints**

- $1 \le a < b \le 10$

**Example**

Input:

`3 10`

Output:

`0.124938737`