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: ['6433', 'L', 'c', '7487', '4773', 'd']

6433, 12, 3, 7487, 4773, 4