TASK 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.
PROBLEM: ['1107', 'C', '5921', '7815', '1509', 'l']

SOLUTION: 1107, 3, 5921, 7815, 1509, 12

PROBLEM: ['5545', '7973', 'M', 'y', '8231', 'D', '7831', '91', '5517', 'd', 'E', 'Y', 'S', 'c', '8775', '4131', '1279', 'b', 'M']

SOLUTION: 5545, 7973, 13, 25, 8231, 4, 7831, 91, 5517, 4, 5, 25, 19, 3, 8775, 4131, 1279, 2, 13

PROBLEM: ['r', 'E', '5611', '5407', '9297', '9563', 'C', 'd', 'D', 'W', '9751', '8139', 'S', '4437', '2331', '2487', 'r', '5649', '5099', '1255', '5865', 'Y', '1477', '1939', '9525', '6353', '7327', '5043', '2837', 'N', 't', 'R', 'R', 'T', 'Z', '353', '7545', 'V', '9287', '8973']

SOLUTION:
18, 5, 5611, 5407, 9297, 9563, 3, 4, 4, 23, 9751, 8139, 19, 4437, 2331, 2487, 18, 5649, 5099, 1255, 5865, 25, 1477, 1939, 9525, 6353, 7327, 5043, 2837, 14, 20, 18, 18, 20, 26, 353, 7545, 22, 9287, 8973