using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[] NMi => ReadLine().Split().Select(c => int.Parse(c) - 1).ToArray();
    static int[][] NMap(int n) => Enumerable.Repeat(0, n).Select(_ => NMi).ToArray();
    public static void Main()
    {
         Solve();
    }
    static void Solve()
    {
        var n = NN - 1;
        var len = n / 36 + 1;
        var num = n % 36;
        for (var a = 1; a <= 9; ++a) for (var b = a + 1; b <= 9; ++b)
        {
            if (num == 0)
            {
                Write(a);
                WriteLine(string.Concat(Enumerable.Repeat((char)(b + '0'), len)));
                return;
            }
            --num;
        }
    }
}