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: ['3359', 'l', 'M', 'S', '6709', 'o', 'z', '9721', '1733', 'D', 'c', '6327', '6217', 'g', '9015', '5421', 'T', 'i']

3359, 12, 13, 19, 6709, 15, 26, 9721, 1733, 4, 3, 6327, 6217, 7, 9015, 5421, 20, 9