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: ['s', '4507', '129', '5449', '7023', 'c', 'O', '1095']

19, 4507, 129, 5449, 7023, 3, 15, 1095