This kata is all about adding numbers.
You will create a function named add. This function will return the sum of all the arguments. Sounds easy, doesn't it??
Well here's the twist. The inputs will gradually increase with their index as parameter to the function.
```python
  add(3,4,5) #returns (3*1)+(4*2)+(5*3)=26
```
Remember the function will return 0 if no arguments are passed.
## Example
```python
  add() #=> 0
  add(1,2,3) #=> 14
  add(1,4,-5,5) #=> 14
```
def add(*args):
    return sum((i+1)*v for i,v in enumerate(args))
def add(*args):
    return sum((i+1)*v for i,v in enumerate(args))