using System;
using System.Globalization;
public class Program
{
public static void Main()
Console.WriteLine(DateTime.ParseExact("01/01/2021", "dd/MM/yyyy", CultureInfo.InvariantCulture));
//Console.WriteLine(DateTime.ParseExact("jan/21", "dd/MM/yyyy", CultureInfo.InvariantCulture));
//Console.WriteLine(DateTime.ParseExact("01/13/2021", "dd/MM/yyyy", CultureInfo.InvariantCulture));
//Console.WriteLine(DateTime.ParseExact("40/01/2021", "dd/MM/yyyy", CultureInfo.InvariantCulture));
}