using System.Collections.Generic;
using System;

public class Hello
{
    static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        getAns(n);
    }
    static void getAns(int n)
    {
        var a = new List<int>();
        for (int i = 1; i <= 8; i++)
            for (int j = i + 1; j <= 9; j++) a.Add(i * 10 + j);
        if (n <= 36) { Console.WriteLine(a[n - 1]); return; }
        var s = (n-1) / 36;
        var r = n % 36;
        if (r - 1 < 0) r += 36;
        Console.Write(a[r - 1]);
        var c = a[r - 1] % 10;
        for (int i = 0; i < s; i++) Console.Write(c);
        Console.WriteLine();
    }
}