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.

2, 5, ['f', 'd', '2691', 't', 'u']
ut1962d

1, 1, ['W', '3467']
W

3, 9, ['H', '2451', 'L', 'H', 'n', '6931', '6681', 'q', 'Q', 'b', 'U']

Qq18661396nHL