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: ['u', '3239', '9145', 'H', 'a', 's', 'o']

21, 3239, 9145, 8, 1, 19, 15