// https://www.newtonsoft.com/json/help/html/SelectToken.htm

​

using System;

using System.IO;

​

public class Program

{

    public static void Main()

    {

        var u1 = @"\\sacfs1\Data\Apps\MarketIntelligence\Feeds\InSyncModels\UAT\incoming\InSync";

        var u2 = @"\3711.TW\3Q19\083019\";

        Console.WriteLine(Path.Combine(u1,u2));

        var u3 = @"\\sacfs1\Data\Apps\MarketIntelligence\Feeds\InSyncModels\UAT\incoming\InSync";

        var u4 = @"3711.TW\3Q19\083019\";

        Console.WriteLine(Path.Combine(u3,u4));

    }

}