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Tight words
Time Limit:1000MS  Memory Limit:1024K

Description:

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

Sample Output:

100.00000
40.74074
17.38281
0.10130
Status  Submit


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