[evzhang] create solution.
[evzhang] tasks for main questions.
[evzhang] calculate one intergalactic number
[evzhang] calculate intergalactic numbers of large to small
[evzhang] calculate intergalactic numbers
[evzhang] calculate total price of intergalactic things
[evzhang] return error message with unidentified input
[evzhang]  deal with thing price of decimal
[evzhang] add test for all inputs
remove file
Add readme