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.

[EX Q]: 8, 16, ['7751', 'Q', '9819', 'k', 'g', 'y', 'W', 'I', '6371', '9859', 'f', '7055', 's', 'I', 'W', '3029']
[EX A]: 9203WIs5507f95891736I

[EX Q]: 3, 6, ['e', 'w', '503', '2677', '4099', 'F', '4781', '3995', '8221', 'z', '6689', 'L', '3821', 'b', 'A', 'P', '4037', 'v', 'M', '3919']
[EX A]: F99047762305

[EX Q]: 7, 20, ['K', 'I', '8685', '4137', 'C', 'c', 'k', 'u', '2537', '6457', 'y', 'm', 'P', '3143', 'v', '6327', 'i', 'G', 'v', 'l', 'T', 't', 'T', '1', '8329', 'b', '8145', 'a']
[EX A]:
lvGi7236v3413Pmy75467352uk