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: ['S', 'K', 't', 'f', '7515', '9925', 'H', '1983', '7599', 'O', 'S', '9887', '8951', '2661', 'X', '4035', '309', '1193', 's', 'Z', '4035', '6145', 'V']

19, 11, 20, 6, 7515, 9925, 8, 1983, 7599, 15, 19, 9887, 8951, 2661, 24, 4035, 309, 1193, 19, 26, 4035, 6145, 22