List 18/18

n = [[1, 2, 3], [4, 5, 6, 7, 8, 9]]
# Add your function here
def flatten(lists):
#indent 1
results = []
for numbers in lists:
#indent 2
for item in numbers:
#indent 3
results.append(item)
#indent 1
return results
#no indent
print flatten(n)