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: ['M', 'r', '1845', 'U', 'M', 'k', '3919', '6915', 'Q', '6063', 'F', 'C', '3031', '8591', 'o', '1839', '1575', '7569']

13, 18, 1845, 21, 13, 11, 3919, 6915, 17, 6063, 6, 3, 3031, 8591, 15, 1839, 1575, 7569