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
//package sept;

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



public class TimePass implements Runnable {
    InputStream is;
    PrintWriter out;
    String INPUT = "10000000";
    //boolean debug=false;
    boolean debug=true;
    static long mod=998244353;
    static long mod2=1000000007;
    
    void solve() throws IOException
	{
    	
    	int n=ni();
    	//long[][] dp=new long[2][n+1];
    	//dp[1][0]=1;
    	//dp[0][0]=3;
    	long[] c=new long[2];
    	long[] p=new long[] {0,1};
    	for(int i=1;i<=n;i++)
    	{
    		//dp[1][i]=(3*dp[0][i-1])%mod2;
    		//dp[0][i]=(dp[1][i-1]+2*dp[0][i-1])%mod2;
    		
    		c[1]=(3*p[0])%mod2;
    		c[0]=(p[1]+2*p[0])%mod2;
    		
    		p[0]=c[0];
    		p[1]=c[1];
    	}
    	out.println(c[1]);
	}
    
    static long[][] dp;
    
    static long comp(int n,int k)
    {
    	if(k==1)
    	{
    		dp[n][k]=1;
    		return 1;
    	}
    	if(dp[n][k]!=0)return dp[n][k];
    	long ans=0;
    	int cnt=0;
    	for(int i=1;i<=Math.sqrt(n);i++)
    	{
    		if(n%i==0)
    		{
    			cnt++;
    			ans=(ans+comp(i,k-1))%mod2;
    			int j=n/i;
    			if(n%j==0 && i!=j)
    			{
    				cnt++;
    				ans=(ans+comp(j,k-1))%mod2;
    			}
    		}
    	}
    	dp[n][k]=(ans)%mod2;
    	return dp[n][k];
    }
    
    static int[] xor;
    
    static void dfs(int u,int[] a,int[][] g,int[] vis)
    {
    	xor[u]=a[u];
    	
    	vis[u]=1;
    	for(int v:g[u])
    	{
    		if(vis[v]==0)
    		{
    			dfs(v,a,g,vis);
    			xor[u]=xor[u]^xor[v];
    		}
    	}
    }

	static int[][] packD(int n,int[] from,int[] to)
	{
		int[][] g=new int[n][];
		int[] p=new int[n];
		for(int f:from)
		{
			p[f]++;
		}
		int m=from.length;
		for(int i=0;i<n;i++)
		{
			g[i]=new int[p[i]];
		}
		for(int i=0;i<m;i++)
		{
			g[from[i]][--p[from[i]]]=to[i];
		}
		return g;
	}
	    
    static class Pair
    {
        int a,b;
        public Pair(int a,int b)
        {
            this.a=a;
            this.b=b;
            //this.ind=ind;
        }
    }
    
    static long lcm(int a,int b)
    {
        long val=a;
        val*=b;
        return (val/gcd(a,b));
    }
    
    static long gcd(long a,long b)
    {
        if(a==0)return b;
        return gcd(b%a,a);
    }
    
    static int pow(int a, int b, int p)
    {
        long ans = 1, base = a;
        while (b!=0)
        {
            if ((b & 1)!=0)
            {
                ans *= base;
                ans%= p;
            }
            base *= base;
            base%= p;
            b >>= 1;
        }
        return (int)ans;
    }

    static int inv(int x, int p)
    {
        return pow(x, p - 2, p);
    }
    
    public void run()
    {
        if(debug)oj=true;
        is = oj ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);
        
        long s = System.currentTimeMillis();
        try {
			solve();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        out.flush();
        tr(System.currentTimeMillis()-s+"ms");
    }
    
    public static void main(String[] args) throws Exception {new Thread(null,new TimePass(),"Main",1<<26).start();}
    
    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;
    
    private int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }
    
    private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
    private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
    
    private double nd() { return Double.parseDouble(ns()); }
    private char nc() { return (char)skip(); }
    
    private String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    
    private char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }
    
    private char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }
    
    private int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }
    
    private int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
    private void tr(Object... o) { if(!oj)System.out.println(Arrays.deepToString(o)); }
}