import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.io.OutputStream;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.math.BigDecimal;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            long[][] F = new long[1000000+1][4];
            F[1][1]=1;
            F[2][2]=1;
            F[3][3]=1;
            F[3][2]=1;
            F[3][1]=1;
            int N = in.nextInt();
            for(int i=4; i<=N; i++){
                F[i][1] = (F[i-1][2]+F[i-1][3])%1000000007;
                F[i][2] = (F[i-2][1]+F[i-2][3])%1000000007;
                F[i][3] = (F[i-3][1]+F[i-3][2])%1000000007;
            }
            out.println((F[N][1]+F[N][2]+F[N][3])%1000000007);
        }
    }


    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

    }
}