Task: Program Execution
Input (English): Set1: '{3, 5, 6, 11, 13, 14, 15, 17, 18, 19}', Set2: '{1, 3, 4, 8, 11, 17, 18, 19, 20}'. How many elements are there in the union of Set1 and Set2 ?
Output (English): 14