using System;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        string dateStr = "03-06-2020";

        string postdate = DateTime.ParseExact(dateStr, "MM-dd-yyyy", CultureInfo.InvariantCulture).ToString("dd/MM/yyyy", CultureInfo.InvariantCulture);

        Console.WriteLine(postdate);

    }

}