Definition: In this task, you are given inputs i,j, and A, where i and j are integers and A is a list. You need to concatenate all elements of A from the ith element to the jth element, and print the resultant 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.
Input: 2, 20, ['O', '6321', '6123', '4459', 'Q', 'K', 'Q', 'r', '3107', '6057', '181', 'i', 'a', '3187', '5439', 'U', 'Y', '749', 'o', '7979']

632161234459QKQr31076057181ia31875439UY749o7979