package no314;

import java.util.Scanner;

public class Main {
	public static final long MOD = 1000000007;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long[][] dp = new long[n+1][3];
		dp[0][0] = 1;
		for(int i=0;i<n;i++) {
			for(int j=0;j<3;j++) {
				if (j > 0) {
					dp[i+1][0] = (dp[i+1][0] + dp[i][j]) % MOD;
				}
				if (j < 2) {
					dp[i+1][j+1] = (dp[i+1][j+1] + dp[i][j]) % MOD;
				}
			}
		}
		long ans = 0;
		for(int i=0;i<3;i++) {
			ans = (ans + dp[n][i]) % MOD;
		}
		System.out.println(ans);
	}

}