instruction:
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.
question:
5, 7, ['2725', '1489', 'P', '2021', 'c', '1605', 'R', 'T', 'p', 'q', '6487', '3395', 'u', 'x']
answer:
R5061c


question:
5, 12, ['t', '4541', 'z', 'K', 'b', 'E', '3395', 'z', '4511', 'F', '7085', '3753', 'n', 'W', 'J']
answer:
35735807F1154z5933Eb


question:
4, 7, ['W', '1199', 'l', '2947', '7847', '3163', '2807', '357', '8901', '1821', 'n', '9811', 'I', 'J', 'c', 'P', 'X', 'U', 'N', '3155', '9235', '9295', 'r', 'C']
answer:

7082361374877492