Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['O', '753', '8999', '187', 'D', 'p', 'V', 'R', '2011', 'k']

15, 753, 8999, 187, 4, 16, 22, 18, 2011, 11