def maxSubArray(nums):
 if len(nums)==0:
 return 0
 else:
 sum_result = nums[0]
 current_value = nums[0]
 for i in range(1,len(nums)):
 if current_value<0:
 current_value = nums[i]
 else:
 current_value += nums[i]
 if current_value>sum_result:
 sum_result = current_value
 return sum_result
def main():
 a = [-2,1,-3,4,-1,2,1,-5,4]
 b = [-1]
 c = [-2,1]
 print(maxSubArray(a))
 print(maxSubArray(b))
 print(maxSubArray(c))
if __name__ == "__main__":
 main()