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: ['U', '647', 'b', '7893', 'j', 'i', '6017', '641', '2339', 'N', '3921', 'x', '7993', '7971', 'h', '9503', 'I', 'p', '4817', 'm', 'E', 'w', 'Z', 'h', '851', '6577', '4905', '7757', '4601', 'T', 'y', 'R', '6027', 'z', 'v', '1419', '7827']

21, 647, 2, 7893, 10, 9, 6017, 641, 2339, 14, 3921, 24, 7993, 7971, 8, 9503, 9, 16, 4817, 13, 5, 23, 26, 8, 851, 6577, 4905, 7757, 4601, 20, 25, 18, 6027, 26, 22, 1419, 7827