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: ['3491', 'A', '5107', 'W', 'p', '7913', 'E', 'm', 'M', 'O', 'f', 'a', 'n', 'A', '3595', 'Q', '815', 'x', '8725', '9387', '6357', '6629', '5089', '21', 'X', '9635']

3491, 1, 5107, 23, 16, 7913, 5, 13, 13, 15, 6, 1, 14, 1, 3595, 17, 815, 24, 8725, 9387, 6357, 6629, 5089, 21, 24, 9635