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: ['1557', 'X', 'C', '4135', '8245', '7647', '9763', 'd', '4937', '107', 'w', 'O', '2833', '4967', 'e', '3507', '6363', '1933', '4867', '4777', '471']

1557, 24, 3, 4135, 8245, 7647, 9763, 4, 4937, 107, 23, 15, 2833, 4967, 5, 3507, 6363, 1933, 4867, 4777, 471