using System;
using System.Linq;
using System.Collections.Generic;
using System.Globalization;
 
public class Test
{
	public static void Main()
	{
	    var a = new List<int>(){ 1 , 2 , 50 };
        var b = new List<int>(){ 9 , 7 , 2 };
        var ax = a.Select(i => new{ Num = i, FromB = false });
        var bx = b.Select(i => new{ Num = i, FromB = true});
 
        var merged = ax.Concat(bx).OrderBy(x => x.Num); 
 
        foreach(var x in merged)
            Console.WriteLine("Num: {0} From-B? {1}", x.Num, x.FromB);
	}   
}
 
 
 

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