using System; using System.Collections; using System.Collections.Generic; using System.Diagnostics; using System.IO; using System.Linq; using System.Numerics; using System.Text; using System.Text.RegularExpressions; using System.Threading.Tasks; using static System.Math; public static class P { public static void Main() { int n = int.Parse(Console.ReadLine()); for (int i = 2; i <= 100; i++) n = n.ToString().Sum(x => x - '0'); Console.WriteLine(n); } }