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: ['9579', 'x', 'f', 'B', 'x', 'K', '889', '7451', 'C', 't', '1273', '7775', '7415', 'W', '3061', 'I']

9579, 24, 6, 2, 24, 11, 889, 7451, 3, 20, 1273, 7775, 7415, 23, 3061, 9