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:
2, 13, ['o', 'B', '5117', 'h', '3007', '2037', 'j', '2651', 'b', 'b', '8977', 'v', 'U', 'l', '3949', 'e', 'x', '6539', '3663', '1359', '2851']
answer:
Uv7798bb1562j73027003h7115B


question:
7, 14, ['j', '2199', '6995', 't', 'U', 'C', '1589', '7061', '851', 'N', '7923', '7387', '2053', 'L', 'y', '3685', 'X', 'C', '4679', '3691', '2991', 'f']
answer:
L350278373297N15816079851


question:
14, 14, ['q', 'n', '4991', '3813', '6023', '4607', '2969', '8851', '6963', '4383', '1763', '1285', '471', 'a', 'p', '749', '6817', '4873']
answer:

a