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

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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.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.math.BigInteger;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;

/**
 * Works good for CF
 * @author cykeltillsalu
 */
public class Prac {

	//some local config
	static boolean test = false;
	static String testDataFile = "testdata.txt";
	static String feedFile = "feed.txt";
	CompetitionType type = CompetitionType.CF;
	private static String ENDL = "\n";

	// solution
	private void solve() throws Throwable {
		long[] ways = new long[4], tmp = new long[4];;
		long mod = 1000000007L;
		ways[0] = 1;
		int n = iread();
		for (int i = 1; i <= n; i++) {
			for (int j = 0; j < tmp.length; j++) {
				tmp[j] = 0;
			}
			
			for (int j = 0; j < ways.length; j++) {
				for (int k = 0; k < ways.length; k++) {
					if(j == k){
						continue;
					}
					tmp[k] += ways[j];
				}
			}
			
			for (int j = 0; j < tmp.length; j++) {
				ways[j] = tmp[j];
				ways[j] %= mod;
			}
		}
		System.out.println(ways[0]);
	}
	
	public int iread() throws Exception {
		return Integer.parseInt(wread());
	}

	public double dread() throws Exception {
		return Double.parseDouble(wread());
	}

	public long lread() throws Exception {
		return Long.parseLong(wread());
	}

	public String wread() throws IOException {
		StringBuilder b = new StringBuilder();
		int c;
		c = in.read();
		while (c >= 0 && c <= ' ')
			c = in.read();
		if (c < 0)
			return "";
		while (c > ' ') {
			b.append((char) c);
			c = in.read();
		}
		return b.toString();
	}

	public static void main(String[] args) throws Throwable {
		
		if(test){ //run all cases from testfile:
			BufferedReader testdataReader = new BufferedReader(new FileReader(testDataFile));
			String readLine = testdataReader.readLine();
			int casenr = 0;
			out: while (true) {
				BufferedWriter w = new BufferedWriter(new FileWriter(feedFile));
				if(!readLine.equals("input")){
					break;
				}
				while (true) {
					readLine = testdataReader.readLine();
					if(readLine.equals("output")){
						break;
					}
					w.write(readLine + "\n");
				}
				w.close();
				System.out.println("Answer on case "+(++casenr)+": ");
				
				new Prac().solve();
				System.out.println("Expected answer: ");
				
				
				while (true) {
					readLine = testdataReader.readLine();
					
					if(readLine == null){
						break out;
					}
					if(readLine.equals("input")){
						break;
					}
					System.out.println(readLine);
				}
				System.out.println("----------------");
			}
			testdataReader.close();
		} else { // run on server
			new Prac().solve();
		}
		out.close();
	}

	public Prac() throws Throwable {
		if (test) {
			in = new BufferedReader(new FileReader(new File(feedFile)));
		}
	}

	InputStreamReader inp = new InputStreamReader(System.in);
	BufferedReader in = new BufferedReader(inp);
	static BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));
	
	enum CompetitionType {CF, OTHER};
//	BufferedReader in = new BufferedReader(new FileReader("input.txt"));
//	out = new BufferedWriter(new FileWriter("output.txt"));
}