import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

public class SymmetricDifference {
    public static void main(String[] args) {
        Set<String> setA = new HashSet<String>(Arrays.asList("John", "Serena", "Bob", "Mary", "Serena"));
        Set<String> setB = new HashSet<String>(Arrays.asList("Jim", "Mary", "John", "Jim", "Bob"));