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: ['3801', '2439', '2509', 'U', 's', 'F', '6471', 'o', '5869', '6693', '9551', 'Q', 'X', 'W', 'n', 'r', 'a', '6393', '697', 'y', '2929', 'k', '8357']

3801, 2439, 2509, 21, 19, 6, 6471, 15, 5869, 6693, 9551, 17, 24, 23, 14, 18, 1, 6393, 697, 25, 2929, 11, 8357