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', '9845', '1599', '7901', '4987', '17', '2053', 'm', 'l', '1923', '9157', '817', '5361', '655', '2393', '8321', 's', '8605', 'l']

15, 9845, 1599, 7901, 4987, 17, 2053, 13, 12, 1923, 9157, 817, 5361, 655, 2393, 8321, 19, 8605, 12