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: ['1861', '7865', 'u', '3451', '7603', 'V', '2389', '4539', '8429', 'x', '6477', '6791', 'Q', '871', '3777', '3011', '139', '1187', 'Z', 'r', '643', '9573', 't', '3541', 'C', 'w', '4301']

1861, 7865, 21, 3451, 7603, 22, 2389, 4539, 8429, 24, 6477, 6791, 17, 871, 3777, 3011, 139, 1187, 26, 18, 643, 9573, 20, 3541, 3, 23, 4301