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: ['6913', 'w', 'u', 'H', 'h', '9343', 'Z', '6701', '2977', '1715', '7539', 'M', 'O', '5375', '5281', 'V', 'f', '9255', '4699', '6949', 'C', '1451']

6913, 23, 21, 8, 8, 9343, 26, 6701, 2977, 1715, 7539, 13, 15, 5375, 5281, 22, 6, 9255, 4699, 6949, 3, 1451