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:
14, 20, ['9977', 't', 'Y', 'i', '7981', 'a', '1711', '3371', '9143', '3665', '1525', 'y', 'b', '379', 'k', 'T', 'Q', 'D', 'c', '1001', '551', 'Z']
answer:
1001cDQTk973


question:
10, 13, ['D', 'A', '4221', '7301', '1937', 'r', '5105', 'q', 'F', 'j', '9441', '6391', '7081', 'l', '6569', 'i', '8871', '5985']
answer:
180719361449j


question:
2, 16, ['9273', 'x', '8489', '5547', '3905', '1291', '3521', '205', '8549', 'y', 'U', '6919', '9315', '7701', '6965', '4351', '5783', '251', 'T', '3925', 'Q', 'W', '839', '5753', 'f', '6415', 'G', 'z', '7801']
answer:

15345696107751399196Uy945850212531921509374559848x