@ghughes13

Could you please help me with this. I just need to understand the working of below code.

```
n = [[1, 2, 3], [4, 5, 6, 7, 8, 9]]
def flatten(lists):
results = []
for numbers in range(len(lists)): #The length o f "n" is 2 and so the iterations
results.append(numbers) #This should take the first list [1,2,3] and append it to results.Similarly for second iteration it would append [4,5,6,7,8,9]
return results
print flatten(n)
```

Outputs: [0]

**Doubt:**

I have added my understandings as comments in above code. So as per my logic it should output [1,2,3,4,5,6,7,8,9]. Then why does it actually outputs [0]?