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: ['6885', '2817', '8933', 'r', 's', 'M', '397', 'k', 'D', 't', '8611', '1221', '1797']

6885, 2817, 8933, 18, 19, 13, 397, 11, 4, 20, 8611, 1221, 1797