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: 6, 21, ['s', '5521', '6919', '4659', '2249', 'n', '3457', 'Z', '1607', '7177', '9539', 't', 'd', '5663', '1379', '9239', 's', 'M', '8871', '9515', 'e']

n3457Z160771779539td566313799239sM88719515e