Solution.cs

using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.Serialization;
using System.Text.RegularExpressions;
using System.Text;
using System;

class Solution {
    // Complete the dayOfProgrammer function below.
    static string dayOfProgrammer(int year) {
        var day = 13; //default day is 13 because 256-31-28-31-30-31-30-31-31=13 (days of month)
        var month = 9;
        if(year < 1918) { //julian calender
            if(year%4==0)
                day--;
        } else if(year == 1918) {
            day += 13; //skipped 13 days
        } else { //year > 1918
            if(year%400==0 || (year%4==0 && year%100!=0))
                day--;
        }
        return $"{day:00}.{month:00}.{year:0000}";
    }

    static void Main(string[] args) {
        TextWriter textWriter = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

        int year = Convert.ToInt32(Console.ReadLine().Trim());

        string result = dayOfProgrammer(year);

        textWriter.WriteLine(result);

        textWriter.Flush();
        textWriter.Close();
    }
}