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: ['l', 'W', '629', '2027', 'L', '7447', '7539']

12, 23, 629, 2027, 12, 7447, 7539