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: ['6369', 'x', 'r', 'L', 'l', '8433', 'Z', '9925', 'o', '6769', 'z', '1429']

6369, 24, 18, 12, 12, 8433, 26, 9925, 15, 6769, 26, 1429