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: ['6159', 'N', '8133', 'J', '4811', '9289', 'G', 'u', '2907', '9429', 'M', 'h', '169', 'W', '3979', 'W', 'R', '6351', '2395', '8115', '6519', 'V', '7931', '5125', '7603', 'X', 'z', '2875', '1897', 'b', 'c', 'P', '6565', '8659', '1619']

6159, 14, 8133, 10, 4811, 9289, 7, 21, 2907, 9429, 13, 8, 169, 23, 3979, 23, 18, 6351, 2395, 8115, 6519, 22, 7931, 5125, 7603, 24, 26, 2875, 1897, 2, 3, 16, 6565, 8659, 1619