To find max continuous subarray sum of size M

I am new to the competitive programming. I am finding trouble in doing the following problem.

The question is that you have given an array or list. And a number M, now you hav to find the continuous subarray of size M having the largest sum.

For example if list is 4,6,10,8,2,1 and M=3 then largest sum window will be 6,8,10 that is sum equal 24 . So answer will be 24

Can anyone help me regarding this question?

>Solution :

You can edit the list and remove the largest number successively:

list = [4,6,10,8,2,1]
M = 3
result = 0
# to get unique elements
new_list = set(list)

for i in range(M):
   result += max(new_list)
   # removing the largest element from new_list
   new_list.remove(max(new_list))

print(result)