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: ['1211', '7493', 'I', '4937', 'X', 'M', 'R', 'Z', '5377', '7609', 't', 'x', '253', 'f', '8559', 'R', 'W', 'L', '8051', '9385', 'u']

1211, 7493, 9, 4937, 24, 13, 18, 26, 5377, 7609, 20, 24, 253, 6, 8559, 18, 23, 12, 8051, 9385, 21