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: ['6477', 'b', 'i', '5741', '3521', 'U', 'A', 'v', '3729', 'A', 'U', '261', '131', '2263', 'r', '337', '8031', '3779', 'e', '4995', 't', '3703', 'C', '7055', '7531', 'f', 'd', 'U', '9193', 'G', '8307', '9733', 'p']

6477, 2, 9, 5741, 3521, 21, 1, 22, 3729, 1, 21, 261, 131, 2263, 18, 337, 8031, 3779, 5, 4995, 20, 3703, 3, 7055, 7531, 6, 4, 21, 9193, 7, 8307, 9733, 16