CF837D Round Subset

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

Print maximal roundness of product of the chosen subset of length $ k $ .

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.