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: ['939', 'G', '6385', 'i', '7135', '9929', 'i', 'G', '1857', '2081', '9491', 'f', 'p', '9475', '21', 'w', '2225', '5159', 'f', '9117', '9633', '9141', '3953', 'D', 'U', '4673', '3921', '6205', '1637', 'D', '9395', 'S', '3301', '8401', '7455', 'X']

939, 7, 6385, 9, 7135, 9929, 9, 7, 1857, 2081, 9491, 6, 16, 9475, 21, 23, 2225, 5159, 6, 9117, 9633, 9141, 3953, 4, 21, 4673, 3921, 6205, 1637, 4, 9395, 19, 3301, 8401, 7455, 24