题目描述
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.
输入
Input is a sequence of lines, each line contains two integer numbers k and n, 1 <= n <= 100.
输出
For each line of input, output the percentage of tight words of length n over the alphabet {0, 1, ... , k} with 5 fractional digits.
100.00000
40.74074
17.38281
0.10130