using System;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        DateTime day=FirstDateOfWeek(2015,2);

        Console.WriteLine("Hello World"+day.ToString());

    }

    static DateTime FirstDateOfWeek(int year, int weekOfYear)

    {

      DateTime jan1 = new DateTime(year, 1, 1);

      int daysOffset = (int)CultureInfo.CurrentCulture.DateTimeFormat.FirstDayOfWeek - (int)jan1.DayOfWeek;

      DateTime firstMonday = jan1.AddDays(daysOffset);

      int firstWeek = CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(jan1, CultureInfo.CurrentCulture.DateTimeFormat.CalendarWeekRule, CultureInfo.CurrentCulture.DateTimeFormat.FirstDayOfWeek);

      if (firstWeek <= 1)

      {

        weekOfYear -= 1;

      }

      return firstMonday.AddDays(weekOfYear * 7);

    }

}