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: ['8379', '9275', '9687', '6801', '7821', 'x', 'U', '9049', 'l', '8451', 'J', '4729', 'V', 'v', '9669', 'i', 'o', 'k', '2679', 't', 'C']

8379, 9275, 9687, 6801, 7821, 24, 21, 9049, 12, 8451, 10, 4729, 22, 22, 9669, 9, 15, 11, 2679, 20, 3