using System;

public class Program

{

    static int[]dp;

    static int Solve(int n)

    {

        if(n==0)

        {

            return 1;

        }

        if(n<0)

        {

            return 0;

        }

        if(dp[n]==-1)

        {

            dp[n]=Solve(n-1)+Solve(n-3)+Solve(n-5);

        }

        return dp[n];

    }

    public static void Main()

    {

        Console.Write("Enter number=");

        int n=int.Parse(Console.ReadLine());

        dp=new int[n+1];

        for(int i=0;i<n+1;i++)

        {

            dp[i]=-1;

        }

        Console.WriteLine(Solve(n));

    }

}