If this challenge is too easy for you, check out: 
https://www.codewars.com/kata/5cc89c182777b00001b3e6a2
___
Upside-Down Pyramid Addition is the process of taking a list of numbers and consecutively adding them together until you reach one number.
When given the numbers `2, 1, 1` the following process occurs:
```
 2   1   1
   3   2 
     5
```
This ends in the number `5`.
___
### YOUR TASK
Given the right side of an Upside-Down Pyramid (Ascending), write a function that will return the original list.
### EXAMPLE
```python
reverse([5, 2, 1]) == [2, 1, 1]
```
NOTE: The Upside-Down Pyramid will never be empty and will always consist of positive integers ONLY.
def reverse(right):
    
    left = [right[-1]]
    k=right
    for i in range(len(right)-1):
        k=list(map(lambda x,y:x-y,k,k[1:]))
        left.append(k[-1])
    left.reverse()
            
    return left
def reverse(right):
    
    left = [right[-1]]
    k=right
    for i in range(len(right)-1):
        k=list(map(lambda x,y:x-y,k,k[1:]))
        left.append(k[-1])
    left.reverse()
            
    return left