Basic Java App Function to Do Some Calculations (Conversion from PHP)

Hello and welcome, I have a php function which does some calculations and it must be converted (or developed from scratch) to a simple java app that does the same exact thing - it must be developed in Android Studio and then i will integrate it in my app. The java app is very simple, it consist of: -user to select a date -user to enter a number then with today's date and the user selected date we can get the "number of days" for the period in question. After that, we have a set of numbers which are hardcoded, example: "20, 12, 5, 2" and we need to see how many of these numbers can be put in our "number of days". For example: if our number of days is 30, then the result must be: one of 20, and two of 5. (total 30) if our number of days is 33, then the result must be: one of 20, and two of 5, one of 2 and 1 individual item. (total 33) its not difficult once you understand the idea, i have the code in php which does that to facilitate everything happy bidding thank you