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: ['55', '1877', 'M', 'f', '219', 'r', '4163', 'x', 'P', '9085', 'U', 'J', 'w', 'P', 'N']

55, 1877, 13, 6, 219, 18, 4163, 24, 16, 9085, 21, 10, 23, 16, 14