I had a hard time figuring out bug in this. can someone identify the bug n based on question below in 3 or less than 3 lines.

In any event consisting of an integers is given a slice of that OK array is a pair of integers (P,Q) such that (P,Q) lies in the range of 0 to N. A slice (P,Q) of Array A is called non negative if all the elements A[P] A[P+1], A[Q-1],A[Q] are not negative. the sum of the slice (P,Q) of an array is the value A[P] A[P+1], A[Q-1],A[Q] . you are given the implementation of a function given an array A of consisting of N integers and return the maximum sum of any non negative slice in that array function returns -1 if there are no negative slices in that array
Example A[0] = 1, A[1] = 2, A[2] = -3, A[3] = 4, A[4]= 5, A[5] = -6 , the function should return 9.

Def solution ( S) : 

   Max_sum = 0 
   Current_sum = 0 
   Positive = False
   N = len(S)
   For i in range(n):
     Item = S[i]
     If item < 0 : 
        If max_sum < current_sum :
          Max_sum = current_sum 
        current_sum = 0
     Else:
        Positive = True 
        current_sum = +=item 
  if current_Sum> max_sum :
     max_sum = current_sum
  if positive : 
    return max_sum 
  return -1