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: ['869', 'n', '8491', '3849', '8257', 'e', '787', 'I', 'b', 'd', '4125', 'Q', '8475', '449', 'E', '7117', 'r', '4897', 'g', '7967', 'T', '5785', '5561', '523', 'R', 'p', 'K', '805', '3401', 'G', 'V', 'k', 'D', 'm', '5745', 'Y', '2943', 'M', 'x']

869, 14, 8491, 3849, 8257, 5, 787, 9, 2, 4, 4125, 17, 8475, 449, 5, 7117, 18, 4897, 7, 7967, 20, 5785, 5561, 523, 18, 16, 11, 805, 3401, 7, 22, 11, 4, 13, 5745, 25, 2943, 13, 24