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.
12, 15, ['U', 'Q', '8769', '6171', 'C', 'r', 'G', '1863', 'n', '4105', '8955', 'H', '9927', 'q', '7735', '2791', '1629', '37', '8751', 'N', 'H', 'v', 'x', '1397', 'V', 'R', '487', 'S']