**A young child can calculate a sum only if the summands follow in non-decreasing order. For example, he can't calculate sum 1+3+2+1 but he can calculate sums 1+1+2 and 3+3.**

**You've got the sum that was written on the board. Rearrange the summans and print the sum in such a way that the child can calculate the sum.(The sum only contains numbers from 1-9)**