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: ['N', '4287', 'a', '5339', '1453', '275', 'g', 'A', '7137', '9671', 'Z', '7391', 't', '903', 'Y', '2427', '4271', 'z', '2893', '6975', '3393', 't', '1395', 'J']

14, 4287, 1, 5339, 1453, 275, 7, 1, 7137, 9671, 26, 7391, 20, 903, 25, 2427, 4271, 26, 2893, 6975, 3393, 20, 1395, 10