maximum sub array which equals 10

// Pick your language
def max_subarray_sum(lst, k):
    max_sum = 0
    sum = 0
    for i, x in enumerate(lst):
        sum += x
        if i >= k:
            sum -= lst[i - k]
        if i >= k - 1:
            max_sum = max(max_sum, sum)
    return max_sum