You are given a tetrahedron. Let's mark its vertices with letters A, B, C and D correspondingly.

<image>

An ant is standing in the vertex D of the tetrahedron. The ant is quite active and he wouldn't stay idle. At each moment of time he makes a step from one vertex to another one along some edge of the tetrahedron. The ant just can't stand on one place.

You do not have to do much to solve the problem: your task is to count the number of ways in which the ant can go from the initial vertex D to itself in exactly n steps. In other words, you are asked to find out the number of different cyclic paths with the length of n from vertex D to itself. As the number can be quite large, you should print it modulo 1000000007 (109 + 7). 

Input

The first line contains the only integer n (1 ≤ n ≤ 107) — the required length of the cyclic path.

Output

Print the only integer — the required number of ways modulo 1000000007 (109 + 7).

Examples

Input

2


Output

3


Input

4


Output

21

Note

The required paths in the first sample are: 

  * D - A - D
  * D - B - D
  * D - C - D
import java.io.*;
import java.math.*;
import java.util.*;


/**
 *
 * @author Saju
 *
 */

public class Main {

	private static int dx[] = { 1, 0, -1, 0 };
	private static int dy[] = { 0, -1, 0, 1 };

	private static final long INF = Long.MAX_VALUE;
	private static final int INT_INF = Integer.MAX_VALUE;
	private static final long NEG_INF = Long.MIN_VALUE;
	private static final int NEG_INT_INF = Integer.MIN_VALUE;
	private static final double EPSILON = 1e-10;

	private static final int MAX = 100007;
	
	private static final long MOD = 1000000007;

	private static final int MAXN = 10000007;
	private static final int MAXA = 10000009;
	private static final int MAXLOG = 22;

	public static void main(String[] args) throws IOException {

		InputReader in = new InputReader(System.in);
		PrintWriter out = new PrintWriter(System.out);

//		 InputReader in = new InputReader(new FileInputStream("src/test.in"));
//		 PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("src/test.out")));



/*


*/
		
		
		int n = in.nextInt();
		
		long dp[][] = new long[2][n + 1];
		dp[1][0] = 1; 
		dp[0][0] = 0;
		
		for(int i = 1; i <= n; i++) {
			dp[1][i] = (3L * dp[0][i - 1]) % MOD;
			dp[0][i] = ((2L * dp[0][i - 1]) + dp[1][i - 1]) % MOD;
		}
		out.println(dp[1][n]);
		
		out.flush();
		out.close();
		System.exit(0);
	}
	
	
	private static long bigMod(long n, long k, long m) {

		long ans = 1;
		while (k > 0) {
			if ((k & 1) == 1) {
				ans = (ans * n) % m;
			}
			n = (n * n) % m;
			k >>= 1;
		}
		return ans;
	}
	
	private static int ceil(int n, int x) {
		int div = n / x;
		if(div * x != n) {
			div++;
		}
		return div;
	}

	private static class Point {
		double x;
		double y;

		Point(double x, double y) {
			this.x = x;
			this.y = y;
		}

		double getDistance(Point p2) {
			Point p1 = this;
			double dx = p1.x - p2.x;
			double dy = p1.y - p2.y;

			return Math.sqrt((dx * dx) + (dy * dy));
		}
	}

	private static int abs(int x) {
		if (x < 0) {
			return -x;
		}
		return x;
	}

	private static long abs(long x) {
		if(x < 0) {
			return -x;
		}
		return x;
	}

	private static int lcm(int a, int b) {
		return (a * b) / gcd(a, b);
	}

	private static int gcd(int a, int b) {
		if (a == 0)
			return b;
		return gcd(b % a, a);
	}

	private static int log(long x, int base) {
		return (int) (Math.log(x) / Math.log(base));
	}

	private static long min(long a, long b) {
		if (a < b) {
			return a;
		}
		return b;
	}

	private static int min(int a, int b) {
		if (a < b) {
			return a;
		}
		return b;
	}

	private static long max(long a, long b) {
		if (a < b) {
			return b;
		}
		return a;
	}

	private static int max(int a, int b) {
		if (a < b) {
			return b;
		}
		return a;
	}

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

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

		public String next() {
			try {
				while (tokenizer == null || !tokenizer.hasMoreTokens()) {
					tokenizer = new StringTokenizer(reader.readLine());

				}
			} catch (IOException e) {
				return null;
			}
			return tokenizer.nextToken();
		}

		public String nextLine() {
			String line = null;
			try {
				tokenizer = null;
				line = reader.readLine();
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
			return line;
		}

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

		public double nextDouble() {
			return Double.parseDouble(next());
		}

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

		public boolean hasNext() {
			try {
				while (tokenizer == null || !tokenizer.hasMoreTokens()) {
					tokenizer = new StringTokenizer(reader.readLine());
				}
			} catch (Exception e) {
				return false;
			}
			return true;
		}
	}
}
	 	 			 	 	  	 		 			 	 	   	 	