In this task, you are given inputs 'i', 'j', and A, where 'i' and 'j' are integers and A is a list. A list is shown by two brackets and comma-separated numbers and characters inside, like ['1', '12', 'l']. You need to concatenate all elements of A from the ith element to the jth element, and then reverse the resulting string. 'i' and 'j' will be non-negative, and will always have a value less than the length of A. 'i' will always be less than 'j'. Perform the operations in order, i.e., do not reverse first and then concatenate.
20, 21, ['375', 'Z', 'K', '5223', 'D', 'z', 'n', '6075', 'b', 'g', '2505', '329', '3221', 'P', '8117', '7847', '4287', 'a', '5117', 'c', 'z', 'v']