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.

Set1: '{5, 6, 7, 10, 12, 13, 18, 19}', Set2: '{18, 3, 20, 15}'. How many elements are there in the union of Set1 and Set2 ?
11

Set1: '{9, 10, 11, 14}', Set2: '{11}'. How many elements are there in the union of Set1 and Set2 ?
4

Set1: '{2, 3, 4, 7, 9, 10, 13, 19}', Set2: '{12, 5, 6, 7}'. How many elements are there in the union of Set1 and Set2 ?

11