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: ['4615', '2371', 'g', '9469', '2679', '6605', '341', '3519', '1299', '7439', '675', 'S', 't', '6543', '3871', 'w', '4093', 'h', 'U', 'z', 'U', '1851', '6145', 'S', '6361', 'V', 'E', 'p', '6239', 'u', '9499', 'F', 'e', 'C', 'O', '5631', '1407']

4615, 2371, 7, 9469, 2679, 6605, 341, 3519, 1299, 7439, 675, 19, 20, 6543, 3871, 23, 4093, 8, 21, 26, 21, 1851, 6145, 19, 6361, 22, 5, 16, 6239, 21, 9499, 6, 5, 3, 15, 5631, 1407