def max_sub_array_sum(a, size):
  
  max_so_far = 0
  max_ending_here = 0
  for i in range(0, size):
    max_ending_here = max_ending_here + a[i]
    if max_ending_here < 0:
      max_ending_here = 0
    elif (max_so_far < max_ending_here):
      max_so_far = max_ending_here
  return max_so_far
def is_not_prime(n):
    import math
    
    result = False
    for i in range(2,int(math.sqrt(n)) + 1):
        if n % i == 0:
            result = True
    return result