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: ['J', '2491', '135', 'A', '8691', '7881', '1991', '4013', 'W', '4719', '407', '3733', '1895', 'C', 'o', '3085', '8331', '9289', '6697', '1217', '5747']

10, 2491, 135, 1, 8691, 7881, 1991, 4013, 23, 4719, 407, 3733, 1895, 3, 15, 3085, 8331, 9289, 6697, 1217, 5747