using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using System.Numerics;

namespace Solver
{
    class Program
    {
        const int M = 1000000007;
        static void Main()
        {
            var sw = new System.IO.StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            var sc = new Scan();
            int p = sc.Int;
            var dp = new long[p + 1][];
            for (int i = 0; i <= p; i++)
                dp[i] = new long[3];

            dp[0][0] = 1;
            for (int i = 1; i <= p; i++)
            {
                for (int j = 0; j < 10; j++)
                {
//                    if (i == p && j == 0) continue;
                    if (j == 3) continue;

                    for (int k = 0; k < 3; k++)
                        dp[i][(j + k) % 3] += dp[i - 1][k];
                }
            }
            long m = 1;
            ulong n = 1;
            for (int i = 0; i < p; i++)
            {
                m *= 9;
                n *= 10;
            }
            m = (long)(n - (ulong)m) - 1;
            sw.WriteLine(m + dp[p][0]);
            sw.Flush();
        }
    }
    class Scan
    {
        public int Int { get { return int.Parse(Console.ReadLine().Trim()); } }
        public long Long { get { return long.Parse(Console.ReadLine().Trim()); } }
        public string Str { get { return Console.ReadLine().Trim(); } }
        public int[] IntArr { get { return Console.ReadLine().Trim().Split().Select(int.Parse).ToArray(); } }
        public long[] LongArr { get { return Console.ReadLine().Trim().Split().Select(long.Parse).ToArray(); } }
        public double[] DoubleArr { get { return Console.ReadLine().Split().Select(double.Parse).ToArray(); } }
        public string[] StrArr { get { return Console.ReadLine().Trim().Split(); } }
        public List<int> IntList { get { return Console.ReadLine().Trim().Split().Select(int.Parse).ToList(); } }
        public List<long> LongList { get { return Console.ReadLine().Trim().Split().Select(long.Parse).ToList(); } }
        public void Multi(out int a, out int b) { var arr = IntArr; a = arr[0]; b = arr[1]; }
        public void Multi(out int a, out int b, out int c) { var arr = IntArr; a = arr[0]; b = arr[1]; c = arr[2]; }
        public void Multi(out long a, out long b) { var arr = LongArr; a = arr[0]; b = arr[1]; }
        public void Multi(out string a, out string b) { var arr = StrArr; a = arr[0]; b = arr[1]; }
    }
}