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: ['3405', '2395', 'Q', 'R', 'g', 'u', 't', '1321', '4331', '5573', 'C', '3365']

3405, 2395, 17, 18, 7, 21, 20, 1321, 4331, 5573, 3, 3365