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.awt.List;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map.Entry;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.*;
 
 
 
 
public class cool {
 
	private static InputStream stream;
	private static PrintWriter pw;
	
	
	
//	static int a;
//	static int b;
//	static int f = 0;
	static int n;
	static int m;
//	static int[][] arr;
	//static char[][] arr;
	
	static int Arr[];
	static int tree[];
	
	static int time = 0;
	
	static int[][] dir = {{-1,0},{0,1},{1,0},{0,-1}};
 
	static int visited[];
	static int visited2[][];
	static Stack<Integer> stack;
	
//	static ArrayList<Integer> ans;
 
//	static int arr[][];
//	static int arr[];
	static char[][] arr;
	static char[][] ans;
//	static int[][] visited;
//  static int c;
//	static int d[];
//	static int arr[][];
	static ArrayList[] adj;
//	static ArrayList<Integer> ans;
//	static int f;
	static int parent[];
	static int color[];
//	static ArrayList<Integer> comp[];
 
	static int f = 0;
	static int k = 0;
	static int count = 0;
	static int ini[];
	
	static ArrayList<Node> list;
	static ArrayList<Integer> ind;
 
	
	
	public static void main(String[] args){
		//InputReader(System.in);
		pw = new PrintWriter(System.out);
		
		Scanner in = new Scanner(System.in);
 
		int n = in.nextInt();
		in.nextLine();
		
		long d = 1;
		long mod = 1000000007;
		long abc = 0;
		
		for(int i = 1;i<=n;i++){
			long dc = (abc * 3)%mod;
			long abcc = (abc*2 + d)%mod;
			
			d = dc;
			abc = abcc;
		}
		
		pw.print(d);
		
		
		pw.close();
	}
 
	
//	public static void dfs(int a,int p){
//		System.out.println(a);
//		if(a > 30000){
//			return;
//		}
//		
//		if(visited[a] == 1){
//			return;
//		}
//		
//		visited[a] = 1;
//		
//		if(ini[a] != 0){
//			count+= ini[a];
//		}
//		
//		int l = a-p;
//		
//		if(visited[a+l-1] == 0){
//			dfs(a+l-1,a);
//		}else if(visited[a+l] == 0){
//			dfs(a+l,a);
//		}else if(visited[a+l+1] == 0){
//			dfs(a+l+1,a);
//		}
//		
//	}
//	
	public static boolean[] sieveOfEratosthenes(int n)
    {
        
        boolean prime[] = new boolean[n+1];
        for(int i=0;i<n;i++)
            prime[i] = true;
         
        for(int p = 2; p*p <=n; p++)
        {
            
            if(prime[p] == true)
            {
                for(int i = p*2; i <= n; i += p)
                    prime[i] = false;
            }
        }
       
       
        return prime;
    }
	
	
	
	
	
	public static int prev(int i,boolean[] arr){
		
		while(arr[i]){
			if(i == 0){
				if(arr[i]){
					return -1;
				}else{
					return 0;
				}
				
				
			}
			
			
			i--;
			
		}
		
		return i;
		
		
	}
	
	
	public static int next(int i,boolean[] arr){
		
		
		while(arr[i]){
			if(i == arr.length-1){
				if(arr[i]){
					return -1;
				}else{
					return 0;
				}
			}
			
			i++;
		}
		
		
		return i;
	}
	
 
	
	private static Map<String, Integer> sortByValue(Map<String, Integer> unsortMap) {
 
        // 1. Convert Map to List of Map
        LinkedList<Entry<String, Integer>> list =
                new LinkedList<Map.Entry<String, Integer>>(unsortMap.entrySet());
 
        // 2. Sort list with Collections.sort(), provide a custom Comparator
        //    Try switch the o1 o2 position for a different order
        Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
            public int compare(Map.Entry<String, Integer> o1,
                               Map.Entry<String, Integer> o2) {
                return (o1.getValue()).compareTo(o2.getValue());
            }
        });
 
        // 3. Loop the sorted list and put it into a new insertion order Map LinkedHashMap
        Map<String, Integer> sortedMap = new LinkedHashMap<String, Integer>();
        for (Map.Entry<String, Integer> entry : list) {
            sortedMap.put(entry.getKey(), entry.getValue());
        }
 
        /*
        //classic iterator example
        for (Iterator<Map.Entry<String, Integer>> it = list.iterator(); it.hasNext(); ) {
            Map.Entry<String, Integer> entry = it.next();
            sortedMap.put(entry.getKey(), entry.getValue());
        }*/
 
 
        return sortedMap;
    }
 
	
	public static ArrayList<Integer> Range(int[] numbers, int target) {
	  
 
	    int low = 0, high = numbers.length - 1;
	    // get the start index of target number
	    int startIndex = -1;
	    while (low <= high) {
	        int mid = (high - low) / 2 + low;
	        if (numbers[mid] > target) {
	            high = mid - 1;
	        } else if (numbers[mid] == target) {
	            startIndex = mid;
	            high = mid - 1;
	        } else
	            low = mid + 1;
	    }
 
	    // get the end index of target number
	    int endIndex = -1;
	    low = 0;
	    high = numbers.length - 1;
	    while (low <= high) {
	        int mid = (high - low) / 2 + low;
	        if (numbers[mid] > target) {
	            high = mid - 1;
	        } else if (numbers[mid] == target) {
	            endIndex = mid;
	            low = mid + 1;
	        } else
	            low = mid + 1;
	    }
 
	    ArrayList<Integer> list = new ArrayList<Integer>();
	    int c = 0;
	    if (startIndex != -1 && endIndex != -1){
	        for(int i = startIndex;i<=endIndex;i++){
	        	list.add(i);
	        }
	    }
	    
	    
	    return list;
	    
	    
	}
 
	
	
	 private static int root(int Arr[],int i)
	    {
	        while(Arr[ i ] != i)           //chase parent of current element until it reaches root
	        {
	            Arr[ i ] = Arr[ Arr[ i ] ] ; 
	            i = Arr[ i ];
	        }
	        return i;
	    }
	 
	 private static void union(int Arr[],int size[],int A,int B)
	    {
	        int root_A = root(Arr,A);
	        int root_B = root(Arr,B);
	     
	       System.out.println(root_A + " " + root_B);
	        if(root_A != root_B){
	        	 if(size[root_A] < size[root_B ])
	 	        {
	        		 Arr[ root_A ] = Arr[root_B];
	        		 size[root_B] += size[root_A];	 	
	 	        }
	 	        else
	 	        {   	
	 	        	Arr[ root_B ] = Arr[root_A];
	 	        	size[root_A] += size[root_B];	 	   
	 	        }	
	        }
	    }
	 
	 private static boolean find(int A,int B)
	    {
	        if( root(Arr,A)==root(Arr,B) )       //if A and B have the same root, it means that they are connected.
	        return true;
	        else
	        return false;
	    }
	 
	
	
 
 
//	
//	public static void bfs(int i){
//		
//		Queue<Integer> q=new LinkedList<Integer>();
//    	q.add(i);
//    	
//    	visited[i] = 1;
//    	c++;
//    	nodes++;
//    	while(!q.isEmpty()){
//    		int top=q.poll();
//    		
//    		Iterator<Integer> it= arr[top].listIterator();
//    		while(it.hasNext()){
//    			int next =it.next();
//    			
//    			if(visited[next] == 0){
//    				nodes++;
//    				visited[next] = 1;
//    				q.add(next);
//    			}
//    		
//    		}
//    	}
//		
//	}
	
	
	
//	public static void dfs(int i){
//		
//		
//		if(visited[i] == 1){
//			return;
//		}
//		
//		visited[i] = 1;
//		con[c].add(i);
//		//System.out.print(i + " ");
//		for(int j = 0;j<arr[i].size();j++){
//			dfs(arr[i].get(j));
//		}
//		
//	}
//	
//	
//	public static void dfss(int i){
//		if(visited[i] == 1){
//			return;
//		}
//		
//		visited[i] = 1;
//		
//		for(int j = 0;j<arr[i].size();j++){
//			dfss(arr[i].get(j));
//		}
//	//	System.out.println(i);
//		stack.push(i);
//	}
//	
//	public static void reverse(){
//		ArrayList[] temp = new ArrayList[n];
//		
//		for(int i = 0;i<n;i++){
//			temp[i] = new ArrayList();
//		}
//		
//		for(int i = 0;i<n;i++){
//			for(int j = 0;j<arr[i].size();j++){
//				temp[arr[i].get(j)].add(i);
//			}
//		}
//		
//		arr = temp;
//		
//	}
//	
//	
	
	
	
	
	
	
	public static boolean isPrime(int n) {
		// Corner cases
		if (n <= 1)
			return false;
		if (n <= 3)
			return true;
 
		// This is checked so that we can skip 
		// middle five numbers in below loop
		if (n % 2 == 0 || n % 3 == 0)
			return false;
 
		for (int i = 5; i * i <= n; i = i + 6)
			if (n % i == 0 || n % (i + 2) == 0)
				return false;
 
		return true;
	}
	
		 
	 // union code starts	
	
	
	 
	 // union code ends
	
	
	 
//	 // Segment tree code begins
//	 
//	 
//	 static void build(int node,int start,int end)
//	 {
//	 if(start==end)
//	 tree[node]=a[start];
//	 else
//	 {
//	 int mid=(start+end)/2;
//	 build(2*node,start,mid);
//	 build(2*node+1,mid+1,end);
//	 if(tree[2*node]<tree[2*node+1])
//	 tree[node]=tree[2*node];
//	 else
//	 tree[node]=tree[2*node+1];
//	 }
//	 }
//	 
//	 
//	 static void update(int node,int start,int end,int idx,int val)
//	 {
//	 if(start==end)
//	 {
//	 a[idx]=val;
//	 tree[node]=val;
//	 }
//	 else
//	 {
//	 int mid=(start+end)/2;
//	 if(idx>=start&&idx<=mid)
//	 update(2*node,start,mid,idx,val);
//	 else
//	 update(2*node+1,mid+1,end,idx,val);
//	 if(tree[2*node]<tree[2*node+1])
//	 tree[node]=tree[2*node];
//	 else
//	 tree[node]=tree[2*node+1];
//	 }
//	 }
//	 
//	 static int query(int node,int start,int end,int l,int r)
//	 {
//	 if(l>end||start>r)
//	 return 100005;
//	 if(l<=start&&r>=end)
//	 return tree[node];
//	 int p1,p2;
//	 int mid=(start+end)/2;
//	 p1=query(2*node,start,mid,l,r);
//	 p2=query(2*node+1,mid+1,end,l,r);
//	 if(p1<p2)
//	 return p1;
//	 else
//	 return p2;
//	 }
//	 
//	 
//	 
//}
 
}
 
class Field{
	
	long a;
	long b;
	
	Field(long a,long b){
		this.a = Math.min(a, b);
		this.b = Math.max(a, b);
	}
	
	boolean greator(Field f){
		return (this.a >= f.a && this.b >= f.b);
	}
	
}
 
 
class Node{
	point a;
	int b;
}
 
class point{
	int a;
	int b;
}
 
 
class MyComp2 implements Comparator<Node>{
    
	@Override
	public int compare(Node o1, Node o2) {
		
//		if((o1.b - o2.b) < 0.00000001){
//			return 0;
//		}else 
		if(o1.b == o2.b){
			return 0;
		}else if( o1.b > o2.b){
			return 1;
		}else if( o2.b > o1.b){
			return -1;
		}
		return 0;
		
	}
}
 
 
class Card implements Comparable<Card>
{
	int a,b;
	public Card(int w,int h)
	{
		this.a=w;
		this.b=h;
		
	}
	public int compareTo(Card that)
	{
		return this.a-that.a;
	}
}