URI Online Judge | 2154
# Polynomial Derivative

**Timelimit: 1**

By Ricardo Martins, IFSULDEMINAS Brazil

The calculation of a derivative of a function in the form x^{n} is defined by:

f(x) = x^{n} → f(x)’ = n.x^{n-1}

Here's an example:

f(x) = 4x^{3} + 3x^{2} → f(x)’ = 12x^{2 }+ 6x

Write a program that, given a simple polynomial, calculate its derivative.

There will be several test cases. Each test case is formed by an integer **T**, which is the number of terms that has the polynomial. In the next line, there is the polynomial itself, formed by **T** ( 1 ≤ **T** ≤ 100) terms, each separated by a space, a sum signal and another space, and each containing an integer **C** ( 2 ≤ **C** ≤ 100), the letter ** x** and an integer

For each test case, print the polynomial with the derivative applied.

Input Sample | Output Sample |

2 7x3 + 3x2 3 3x4 + 4x3 + 2x2 |
21x2 + 6x 12x3 + 12x2 + 4x |