Round Subset
题目描述
Let's call the roundness of the number the number of zeros to which it ends.
You have an array of n numbers. You need to choose a subset of exactly k numbers so that the roundness of the product of the selected numbers will be maximum possible.
The first line contains two integer numbers n and k (1≤n≤200,1≤k≤n).
The second line contains n space-separated integer numbers a1,a2,...,an (1≤ai≤1018).
Print maximal roundness of product of the chosen subset of length k.
3 2
50 4 20
3
5 3
15 16 3 25 9
3
3 3
9 77 13
0
In the first example there are 3 subsets of 2 numbers. [50,4] has product 200 with roundness 2, [4,20] − product 80, roundness 1, [50,20] − product 1000, roundness 3.
In the second example subset [15,16,25] has product 6000, roundness 3.
In the third example all subsets has product with roundness 0.
题目来源：fps-www.educg.net-codeforce-1-2833.xml.zip；FPS 共享题包，题包内第 79 题。保留原作者与原赛事署名。