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: ['i', '1159', '1003', '6603', 'N', '5743', '2255', '569', '4573', 'L', '6631', 'L', '1415', 'f']

9, 1159, 1003, 6603, 14, 5743, 2255, 569, 4573, 12, 6631, 12, 1415, 6