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', 'L', '831', '9817', '4185', '4721', 'D', '4839', 'W', '8707', '9871', 'r', 'H', '4007', '6675', 'd', 'z', '7435', 'n', '5155', '2737', '4089', 'd', 'w', 'Y', 'k', 'd', 'u', 'L', '5705', '817']

6, 12, 831, 9817, 4185, 4721, 4, 4839, 23, 8707, 9871, 18, 8, 4007, 6675, 4, 26, 7435, 14, 5155, 2737, 4089, 4, 23, 25, 11, 4, 21, 12, 5705, 817