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: ['u', 'n', '2763', 'n', '5869', 'w', '4847', '4369', '8245', '9801', 'W', '7991', 't', '9233', 'Z', '3521', 'Z', 'H', 'N', 'a', '9811', '5705', '6637', '5067', 'o']

21, 14, 2763, 14, 5869, 23, 4847, 4369, 8245, 9801, 23, 7991, 20, 9233, 26, 3521, 26, 8, 14, 1, 9811, 5705, 6637, 5067, 15