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: ['999', '2137', 'A', 'k', '7677', 'b', 'b', '3907', '4563', 't', '6537', '6963', 'Q', 'F', 'f', 'M', 'i', '7903', '1711', 'e', '5553', 'Z', 'o', '3595', 'O', 's', '55', '2119', '913', 'n', 'd', 'z', 'R', '1593', 'Y', '9659']

999, 2137, 1, 11, 7677, 2, 2, 3907, 4563, 20, 6537, 6963, 17, 6, 6, 13, 9, 7903, 1711, 5, 5553, 26, 15, 3595, 15, 19, 55, 2119, 913, 14, 4, 26, 18, 1593, 25, 9659