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', '8419', 'p', '2659', 'y', 'e', '3697', '4945', 'S', '6933', 'W', '9691', 'S', '265', 'a', '7625']

19, 8419, 16, 2659, 25, 5, 3697, 4945, 19, 6933, 23, 9691, 19, 265, 1, 7625