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

public class Main {
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		// 入力
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		long[] work = new long[N];
		
		// 計算
		work[0] = 0L;
		if(N > 1){
			work[1] = 3L;
			int MOD = 1000000007;
			for(int i = 2; i < N; i++){
				long w1 = (work[i-2] * 3) % MOD;
				long w2 = (work[i-1] * 2) % MOD;
				work[i] = (w1 + w2) % MOD;
			}
		}
		
		// 出力
		System.out.println(work[N-1]);
	}

}