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: ['809', 'p', 'W', 'U', 'I', '1841', 'd', 'M', 'm', '9495', '2221', '9411', 'r', 'A', '8749', '683', 'k', '6613', '9079', 'I', 'g', '139']

809, 16, 23, 21, 9, 1841, 4, 13, 13, 9495, 2221, 9411, 18, 1, 8749, 683, 11, 6613, 9079, 9, 7, 139