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: ['3479', 'C', '7317', '1173', '8763', '5609', 'd', '899', 'o']

3479, 3, 7317, 1173, 8763, 5609, 4, 899, 15