this is my code

n = [3, 5, 7]

```
def total(numbers):
result=0
for i in range(len(numbers)):
result= i +result
return result
```

error massage (Oops, try again.

total([0, 3, 6]) returned 3 instead of 9)

this is my code

n = [3, 5, 7]

```
def total(numbers):
result=0
for i in range(len(numbers)):
result= i +result
return result
```

error massage (Oops, try again.

total([0, 3, 6]) returned 3 instead of 9)

The for loop you created will just be numbers at each iteration. The intent here is that each number is a valid index in the given list. hence you must modify this line

`result= i +result`

to be

`result= numbers[i] +result`

```
n = [[1, 2, 3], [4, 5, 6, 7, 8, 9]]
# Add your function here
def flatten(lists):
results=[]
for numbers in lists:
for x in numbers:
results.append(x)
return results
print flatten(n)
```