import java.io.*;
import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int[][] dp = new int[Math.max(4, n + 1)][3];
        dp[1][0] = 1;
        dp[2][1] = 1;
        dp[3][0] = 1;
        dp[3][1] = 1;
        dp[3][2] = 1;
        for (int i = 4; i <= n; i++) {
            dp[i][0] = (dp[i - 1][1] + dp[i - 1][2]) % MOD;
            dp[i][1] = (dp[i - 2][0] + dp[i - 2][2]) % MOD;
            dp[i][2] = (dp[i - 3][0] + dp[i - 3][1]) % MOD;
        }
        int ans = ((dp[n][0] + dp[n][1]) % MOD + dp[n][2]) % MOD;
        System.out.println(ans);
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}