In this task, you are given two sets, and you need to count the number of elements at the union of two given sets. A Set is shown by two curly braces and comma-separated numbers inside, like {1, 2, 3}. Union of two given sets is the smallest set which contains all the elements of both the sets. To find the union of two given sets, A and B is a set that consists of all the elements of A and all the elements of B such that no element is repeated.
--------
Question: Set1: '{14, 15}', Set2: '{7, 9, 13, 14, 18, 19}'. How many elements are there in the union of Set1 and Set2 ?

Answer: 7


Question: Set1: '{2, 4, 5, 9, 10, 15, 17, 20}', Set2: '{4, 6, 10, 11, 15, 17, 18, 20}'. How many elements are there in the union of Set1 and Set2 ?

Answer: 11


Question: Set1: '{4, 5, 8, 13, 15, 16, 18, 20}', Set2: '{3, 7, 10, 12, 16}'. How many elements are there in the union of Set1 and Set2 ?

Answer:
12