using System;

using System.Collections.Generic;

using System.Linq;

​

public class MergeNames

{

    public static IEnumerable<string> UniqueNames(string[] names1, string[] names2)

    {   

        var uniqueNames = new List<string>();

        return names1.Concat(names2).Distinct();

    }

    public static void Main(string[] args)

    {

        string[] names1 = new string[] {"Ava", "Emma", "Olivia", "Emma"};

        string[] names2 = new string[] {"Olivia", "Sophia", "Emma", "Sophia"};

        IEnumerable<string> mergedNames = UniqueNames(names1, names2);

        mergedNames.Dump();

    }

}