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: ['6649', 'r', 's', '5571', 'd', '6391', 'b', '4441', '8659', '4249', '4725', 'u', '5657', '2745', '5103', '5181', '9827', 'j', '447', 'Z']

6649, 18, 19, 5571, 4, 6391, 2, 4441, 8659, 4249, 4725, 21, 5657, 2745, 5103, 5181, 9827, 10, 447, 26