Problem Description
Oaiei is a good boy who loves math very much, he would like to simplify some mathematical expression, can you help him?
For the sake of simplicity, the form of expression he wanted to simplify is shown as follows:

General characters

num: an integer (0 <= num <= 1000)
 X: unknown variable
 X^num: num power of X
 numX: the coefficient of the unknown variable X is num

Connector character

+: General characters connected with the character which expresses the addition
 : General characters connected with the character which expresses the subtraction
Given the expression, your task is conversion the expression to the simplest form.
Input
Given the expression S, the length of S is less than 200, there is no space in the given string.
Output
Output the simplest expression S’, you should output S’ accordance to the X with descending order of power. Note that X^1 need only output X, 1X need only output X.
Sample Input
4X^5+8X^5+4X+3X^0+8
4X^53X^5
Sample Output
12X^5+4X+11
7X^5
Source
FOJ月赛2008年5月