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: ['3669', '7527', '6919', '87', '985', 'x', 'x', 'U', 's', 'M']

3669, 7527, 6919, 87, 985, 24, 24, 21, 19, 13