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: ['9711', 'F', '213', '8235', 'n', 'm', '6965', '1095', '4771', 'u', 'Z']

9711, 6, 213, 8235, 14, 13, 6965, 1095, 4771, 21, 26