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: ['1253', '7645', 'Y', '9897', '7047', '7489', 'r', 't', '1509', 'N', 'k', '8791', 'h', 'd', '8567', '2749', '9307', '3421', 'k', '1843', '8475', 'p']

1253, 7645, 25, 9897, 7047, 7489, 18, 20, 1509, 14, 11, 8791, 8, 4, 8567, 2749, 9307, 3421, 11, 1843, 8475, 16