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: ['667', 'b', 'b', 'N', '807', 'P', '1623', '7419', 'M', '8373', 'm', 'a', 'n', '7513']

667, 2, 2, 14, 807, 16, 1623, 7419, 13, 8373, 13, 1, 14, 7513