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: ['6685', '2665', 'R', 'H', '2889', '4143', '7897', '6791', '2309', '2779', '2019', 'j', 'K', '3085', 'z', 'U', 'C', 'T', '6269', '1221', 'c', '8977', 'v', '3523', 'v', '963', '153']

6685, 2665, 18, 8, 2889, 4143, 7897, 6791, 2309, 2779, 2019, 10, 11, 3085, 26, 21, 3, 20, 6269, 1221, 3, 8977, 22, 3523, 22, 963, 153