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: ['C', 'Z', 's', '9939', 'U', '8303', 'q', '7519', 'Y', '501', '7689']

3, 26, 19, 9939, 21, 8303, 17, 7519, 25, 501, 7689