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: ['O', 'B', 'x', 'o', '4575', 'a', '4477', '1091', '855', '7491', '4019', '3827', 'P', '1417', '9783', 's', 'S', 'T', 'K', 'u', 't', 'K', '9203', 'c', '9449', '2311']

15, 2, 24, 15, 4575, 1, 4477, 1091, 855, 7491, 4019, 3827, 16, 1417, 9783, 19, 19, 20, 11, 21, 20, 11, 9203, 3, 9449, 2311