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.*;
import java.util.*;
import java.math.*;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Tetrahedron {
    public static void main(String[] args) throws IOException {
        OutputStream outputStream = System.out;
        Reader in = new Reader();
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }
    static class TaskA {
        int mod = (1000000007);
        public void solve(int testNumber, Reader in, PrintWriter out) throws IOException{
        	while(testNumber-->0){
                int n = in.nextInt();
                int a[] = new int[n+1];
                int b[] = new int[n+1];
                a[0] = 0;b[0] = 1;
                int y = 1;
                for(int i=1;i<=n;i++){
                	int x = a[i-1];
                	b[i] = ((x+x)%mod+x)%mod;
                	a[i] = b[i] + y;
                	y = -y;
                }
                out.println(b[n]);
            }
        }
        class Combine{
            int value;
            int delete;
            Combine(int val , int delete){
                this.value = val;
                this.delete = delete;
            }
        }
        class Sort2 implements Comparator<Combine>{
            public int compare(Combine a , Combine b){
                if(a.value > b.value)
                    return 1;
                else if(a.value == b.value && a.delete>b.delete)
                    return 1;
                else if(a.value == b.value && a.delete == b.delete)
                    return 0;
                return -1;
            }
        }
        class Sort1 implements Comparator<Character>{
        	public int compare(Character a , Character b){
        		char a1 = a.charValue();
        		char b1 = b.charValue();
        		if(a1>b1)
        			return 1;
        		return -1;
        	}
        }
        public void sieve(int a[]){
        	a[0] = a[1] = 1;
        	int i;
        	for(i=2;i*i<=a.length;i++){
        		if(a[i] != 0)
        			continue;
        		a[i] = i;
        		for(int k = (i)*(i);k<a.length;k+=i){
        			if(a[k] != 0)
        				continue;
        			a[k] = i;
        		}
        	}
        }
        public int [][] matrixExpo(int c[][] , int n){
            int a[][] = new int[c.length][c[0].length];
            int b[][] = new int[a.length][a[0].length];
            for(int i=0;i<c.length;i++)
                for(int j=0;j<c[0].length;j++)
                    a[i][j] = c[i][j];
            for(int i=0;i<a.length;i++)
                b[i][i] = 1;
            while(n!=1){
                if(n%2 == 1){
                    b = matrixMultiply(a , a);
                    n--;
                }
                a = matrixMultiply(a , a);
                n/=2;
            }
            return matrixMultiply(a , b);
        }
        public int [][] matrixMultiply(int a[][] , int b[][]){
            int r1 = a.length;
            int c1 = a[0].length;
            int c2 = b[0].length;
            int c[][] = new int[r1][c2];
            for(int i=0;i<r1;i++){
                for(int j=0;j<c2;j++){
                    for(int k=0;k<c1;k++)
                        c[i][j] += a[i][k]*b[k][j];
                }
            }
            return c;
        }
        public long nCrPFermet(int n , int r , long p){
            if(r==0)
                return 1l;
            long fact[] = new long[n+1];
            fact[0] = 1;
            for(int i=1;i<=n;i++)
                fact[i] = (i*fact[i-1])%p;
            long modInverseR = pow(fact[r] , p-2 , 1l , p);
            long modInverseNR = pow(fact[n-r] , p-2 , 1l , p);
            long w = (((fact[n]*modInverseR)%p)*modInverseNR)%p;
            return w;
        }
        public long pow(long a , long b , long res , long mod){
            if(b==0)
                return res;
            if(b==1)
                return (res*a)%mod;
            if(b%2==1){
                res *= a;
                res %= mod;
                b--;
            }
            return pow((a*a)%mod , b/2 , res , mod);
        }
        public long pow(long a , long b , long res){
            if(b == 0)
                return res;
            if(b==1)
                return res*a;
            if(b%2==1){
                res *= a;
                b--;
            }
            return pow(a*a , b/2 , res);
        }
        public void swap(int a[] , int p1 , int p2){
            int x = a[p1];
            a[p1] = a[p2];
            a[p2] = x;
        }
        public void sortedArrayToBST(TreeSet<Integer> a , int start, int end) { 
            if (start > end) {
                return;
            }
            int mid = (start + end) / 2;
            a.add(mid);
            sortedArrayToBST(a, start, mid - 1);
            sortedArrayToBST(a, mid + 1, end); 
        }
        public int lowerLastBound(ArrayList<Integer> a , int x){
            int l = 0;
            int r = a.size()-1;
            if(a.get(l)>=x)
                return -1;
            if(a.get(r)<x)
                return r;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a.get(mid) == x && a.get(mid-1)<x)
                    return mid-1;
                else if(a.get(mid)>=x)
                    r = mid-1;
                else if(a.get(mid)<x && a.get(mid+1)>=x)
                    return mid;
                else if(a.get(mid)<x && a.get(mid+1)<x)
                    l = mid+1;
            }
            return mid;
        }
        public int upperFirstBound(ArrayList<Integer> a , Integer x){
            int l = 0;
            int r = a.size()-1;
            if(a.get(l)>x)
                return l;
            if(a.get(r)<=x)
                return r+1;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a.get(mid) == x && a.get(mid+1)>x)
                    return mid+1;
                else if(a.get(mid)<=x)
                    l = mid+1;
                else if(a.get(mid)>x && a.get(mid-1)<=x)
                    return mid;
                else if(a.get(mid)>x && a.get(mid-1)>x)
                    r = mid-1;
            }
            return mid;
        }
        public int lowerLastBound(int a[] , int x){
            int l = 0;
            int r = a.length-1;
            if(a[l]>=x)
                return -1;
            if(a[r]<x)
                return r;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a[mid] == x && a[mid-1]<x)
                    return mid-1;
                else if(a[mid]>=x)
                    r = mid-1;
                else if(a[mid]<x && a[mid+1]>=x)
                    return mid;
                else if(a[mid]<x && a[mid+1]<x)
                    l = mid+1;
            }
            return mid;
        }
        public int upperFirstBound(long a[] , long x , int l){
            // int l = 0;
            int r = a.length-1;
            if(a[l]>x)
                return l;
            if(a[r]<=x)
                return r+1;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a[mid] == x && a[mid+1]>x)
                    return mid+1;
                else if(a[mid]<=x)
                    l = mid+1;
                else if(a[mid]>x && a[mid-1]<=x)
                    return mid;
                else if(a[mid]>x && a[mid-1]>x)
                    r = mid-1;
            }
            return mid;
        }
        public long log(float number , int base){
            return (long) Math.floor((Math.log(number) / Math.log(base)));
        }
        public long gcd(long a , long b){
            if(a<b){
                long c = b;
                b = a;
                a = c;
            }
            if(a%b==0)
                return b;
            return gcd(b , a%b);
        }
        public void print2d(long a[][] , PrintWriter out){
            for(int i=0;i<a.length;i++){
                for(int j=0;j<a[i].length;j++)
                    out.print(a[i][j] + " ");
                out.println();
            }
            out.println();
        }
        public void print1d(int a[] , PrintWriter out){
            for(int i=0;i<a.length;i++)
                out.print(a[i] + " ");
            out.println();
            out.println();
        }
    }

    static class Reader{ 
        final private int BUFFER_SIZE = 1 << 16; 
        private DataInputStream din; 
        private byte[] buffer; 
        private int bufferPointer, bytesRead; 

        public Reader(){ 
            din = new DataInputStream(System.in); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 

        public Reader(String file_name) throws IOException { 
            din = new DataInputStream(new FileInputStream(file_name)); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 

        public String next() throws IOException { 
            byte[] buf = new byte[64]; // line length 
            int cnt = 0, c; 
            while ((c = read()) != -1) { 
                if (c == '\n') 
                    break; 
                buf[cnt++] = (byte) c; 
            } 
            return new String(buf, 0, cnt); 
        } 

        public int nextInt() throws IOException { 
            int ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do{ 
                ret = ret * 10 + c - '0'; 
            } while ((c = read()) >= '0' && c <= '9'); 

            if (neg) 
                return -ret; 
            return ret; 
        } 

        public long nextLong() throws IOException { 
            long ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
            if (neg) 
                return -ret; 
            return ret; 
        } 

        public double nextDouble() throws IOException { 
            double ret = 0, div = 1; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 

            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 

            if (c == '.') { 
                while ((c = read()) >= '0' && c <= '9') { 
                    ret += (c - '0') / (div *= 10); 
                } 
            } 

            if (neg) 
                return -ret; 
            return ret; 
        } 

        private void fillBuffer() throws IOException { 
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
            if (bytesRead == -1) 
                buffer[0] = -1; 
        } 

        private byte read() throws IOException { 
            if (bufferPointer == bytesRead) 
                fillBuffer(); 
            return buffer[bufferPointer++]; 
        } 

        public void close() throws IOException { 
            if (din == null) 
                return; 
            din.close(); 
        } 
    }
}
