## Problem B: Tight words

Given is an alphabet *{0, 1, ... , k}*, *0 <= k <= 9 *.
We say that a word of length *n* over this alphabet is
*tight* if any two neighbour digits in the word do not differ
by more than 1.
Input is a sequence of lines, each line contains two integer numbers
*k* and *n*, *1 <= n <= 100*. For each
line of input, output the percentage of tight words of length
*n* over the alphabet *{0, 1, ... , k}* with 5 fractional digits.

### Sample input

4 1
2 5
3 5
8 7

### Output for the sample input

100.00000
40.74074
17.38281
0.10130