using System; using System.Linq; namespace No188 { class Program { static void Main(string[] args) { var result = Enumerable.Range(0, int.MaxValue) .Select(i => new DateTime(2015, 1, 1).AddDays(i)) .TakeWhile(date => date.Year == 2015) .Count(date => date.Month == (int)(date.Day * 0.1) + date.Day - (int)(date.Day * 0.1) * 10); Console.Write(result); } } }