from collections.abc import Sequence
def max_subarray_sum(nums: Sequence[int]) -> int:
"""Return the maximum possible sum amongst all non - empty subarrays.
Raises:
ValueError: when nums is empty.
>>> max_subarray_sum([1,2,3,4,-2])
10
>>> max_subarray_sum([-2,1,-3,4,-1,2,1,-5,4])
6
"""
if not nums:
raise ValueError("Input sequence should not be empty")
curr_max = ans = nums[0]
nums_len = len(nums)
for i in range(1, nums_len):
num = nums[i]
curr_max = max(curr_max + num, num)
ans = max(curr_max, ans)
return ans
if __name__ == "__main__":
n = int(input("Enter number of elements : ").strip())
array = list(map(int, input("\nEnter the numbers : ").strip().split()))[:n]
print(max_subarray_sum(array))