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: ['6349', 'c', 'M', 'b', '3175', 'P', '5241', '127', '5387', 'u', '5233', 'm', 's', '5243', 'Z']

6349, 3, 13, 2, 3175, 16, 5241, 127, 5387, 21, 5233, 13, 19, 5243, 26