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: ['1819', 'F', 'A', 'i', 'K', 'x', '1471', '7597', 'c', '8749', 'Y', 'Z', 'L', 'q', 'U', '8125', 'u', 'b']

1819, 6, 1, 9, 11, 24, 1471, 7597, 3, 8749, 25, 26, 12, 17, 21, 8125, 21, 2