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: ['u', 'P', 't', 'E', 'w', '8587', '361', '3863', '8295', '1969', 'D', '7043', 'l']

21, 16, 20, 5, 23, 8587, 361, 3863, 8295, 1969, 4, 7043, 12