using System;

using System.Linq;

using System.Collections;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var dict = Process1().Concat(Process2()).SelectMany(x => x.Select(y => (y.Key, y.Value))).ToDictionary(x => x.Key, x => x.Value);

        foreach (var item in dict)

            Console.WriteLine(item.Key);

    }

    static List<Dictionary<string, object>> Process1() 

    {

        return new List<Dictionary<string, object>>()

        {

            new Dictionary<string, object>() { 

                {"A", "A"},

                {"B", "B"}

            },

            new Dictionary<string, object>() { 

                {"C", "C"},

                {"D", "D"}

            },

        };

    }

    static List<Dictionary<string, object>> Process2() 

    {

        return new List<Dictionary<string, object>>()

        {

            new Dictionary<string, object>() { 

                {"E", "E"},

                {"F", "F"}

            },

            new Dictionary<string, object>() { 

                {"G", "G"},

                {"H", "H"}

            },

        };

    }

}