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: ['1291', '4441', 'T', '571', 'n', 'f', 'W', 'L', '833', 'S']

1291, 4441, 20, 571, 14, 6, 23, 12, 833, 19