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: ['F', 't', '7155', '3521', 'Q', 'I', 'E', 'B', 'U', '9743', '5921', '7733', 'V', '3439', '4357', 'r', '1181', 'y', 'a']

6, 20, 7155, 3521, 17, 9, 5, 2, 21, 9743, 5921, 7733, 22, 3439, 4357, 18, 1181, 25, 1