Write a function named

`append_sum`

that has one parameter — a list named named`lst`

.The function should add the last two elements of

`lst`

together and append the result to`lst`

. It should do this process three times and then return`lst`

.For example, if

`lst`

started as`[1, 1, 2]`

, the final result should be `[1, 1, 2, 3, 5, 8]

I’m not sure why, but I am having trouble with this. Essentially, I can’t wrap my head around how to access the last two values inside the list, index -1 and -2, and append it to the list while adding them together. I believe it is something simple…but brain no work

```
def append_sum(lst):
add = lst[-2:]
lst = lst.append(add[0] + add[1])
print[lst]
#Uncomment the line below when your function is done
print(append_sum([1, 1, 2]))
```