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: ['5423', '6083', '7525', '6153', 'x', 'Z', '4889', 'U', 'X']

5423, 6083, 7525, 6153, 24, 26, 4889, 21, 24