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, 19, ['623', 'k', '1127', '1235', '5469', 'U', '3735', '6967', 'm', '2135', 'X', 'X', '1779', 'b', '3319', '2465', 'Z', 'f', 'f', '1031', 'n', 'K']

U37356967m2135XX1779b33192465Zff