using System; public class Program { public static void Main() { DateTime dateTime = new DateTime(2015,1,1); int happyday = 0; for (int i = 1;i < 365;i++) { DateTime addday = dateTime.AddDays(i); //Console.WriteLine(addday.ToString()); if (addday.Day.ToString().Length == 2) { int dayten = int.Parse(addday.Day.ToString().Substring(0, 1)); int dayone = int.Parse(addday.Day.ToString().Substring(1, 1)); //Console.WriteLine("{0} {1}",dayten,dayone); if(dayten + dayone == addday.Month) { happyday++; } } else if(addday.Day == addday.Month) { happyday++; } } Console.WriteLine("{0}", happyday); } }