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, 5, ['f', 'd', '2691', 't', 'u']
answer:
ut1962d


question:
1, 8, ['7991', '7999', '8575', '4211', '6003', '2483', '7877', '7249', 'K', '21']
answer:
94277787384230061124575899971997


question:
23, 26, ['c', '2231', 'f', '4261', 'x', '8511', '6147', 'n', 'M', '4859', 'p', '1033', '2031', 'A', 'c', '377', '4309', 'r', '7031', 'i', '3619', '3767', '2001', 'g', 'u', 'C', '341', '4457', 'y', '2221']
answer:

Cug1002