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: 10, 21, ['2631', '1899', 'W', '1377', 'P', '8069', 'h', 'x', '9563', '3029', '3971', '7629', 'u', '5827', 't', 'e', 'i', '9473', 'O', '6407', 'j']

302939717629u5827tei9473O6407j