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: ['S', 'E', 'R', 'U', 'a', '2031', 'e', 'I', 'M', 'B', '7843', 'u', 'q', 'F', '1935', 'g', 'L', '3759', '7557', '9687', 'L', 'r', 'H', '8233', '7427', 'u', 'Z', '7445', '1867', 'C', 'g', '1399']

19, 5, 18, 21, 1, 2031, 5, 9, 13, 2, 7843, 21, 17, 6, 1935, 7, 12, 3759, 7557, 9687, 12, 18, 8, 8233, 7427, 21, 26, 7445, 1867, 3, 7, 1399