# Codility – Tape equilibrium training using Python

A non-empty zero-indexed array A consisting of N integers is given. Array A represents numbers on a tape. Any integer P, such that 0 < P < N, splits this tape into two non-empty parts: A, A, …, A[P − 1] and A[P], A[P + 1], …, A[N − 1]. The difference between the two parts is the value of: |(A + A + … + A[P − 1]) − (A[P] + A[P + 1] + … + A[N − 1])| In other words, it is the absolute difference between the sum of the first part and the sum of the second part.

```def solution(A):
N = len(A)
my_list = []
for i in range(1, N):
first_tape = sum(A[:i - 1]) + A[i]
second_tape = sum(A[i - 1:]) + A[i]
difference = abs(first_tape - second_tape)
my_list.append(difference)
print(min(my_list))
return min(my_list)
```

My solution gets 100% on Correctness but 0% on Performance. I think it is supposed to be O(N) but my time complexity is O(N*N). Can anyone please give me advice please?

You can change your code to something like below to have complexity `O(N)`.
```def solution(A):