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.util.*;

public class Main {
	static int mod = 1000000007;
  static int size = 200000;
	static long[] fac = new long[size];
	static long[] finv = new long[size];
	static long[] inv = new long[size];
	static int INF = Integer.MAX_VALUE;

 	public static void main(String[] args){
		Scanner scanner = new Scanner(System.in);
		int n = scanner.nextInt();
		//dp[i][j]:=i秒後にjにいる場合の数
		long d = 1;
		long abc = 0;
		for(int i = 1; i <= n; i++){
			long nd = 3L * abc;
			nd %= mod;
			long nabc = abc*2L+d;
			nabc %= mod;
			d = nd;
			abc = nabc;
		}
		System.out.println(d);
	}
	public static class Edge{
		int to;
		Edge(int to){
			this.to = to;
		}
	}
	public static void swap(long a, long b){
		long tmp = 0;
		if(a > b){
			tmp = a;
			a = b;
			b = tmp;
		}
	}
  static class Pair implements Comparable<Pair>{
    int first, second;
    Pair(int a, int b){
        first = a;
        second = b;
    }
    @Override
    public boolean equals(Object o){
        if (this == o) return true;
        if (!(o instanceof Pair)) return false;
        Pair p = (Pair) o;
        return first == p.first && second == p.second;
    }
    @Override
    public int compareTo(Pair p){
        //return first == p.first ? second - p.second : first - p.first; //firstで昇順にソート
        //return (first == p.first ? second - p.second : first - p.first) * -1; //firstで降順にソート
        return second == p.second ? first - p.first : second - p.second;//secondで昇順にソート
        //return (second == p.second ? first - p.first : second - p.second)*-1;//secondで降順にソート
    }
  }

  //繰り返し二乗法
  public static long pow(long x, long n){
    long ans = 1;
    while(n > 0){
      if((n & 1) == 1){
        ans = ans * x;
        ans %= mod;
      }
      x = x * x % mod;
      n >>= 1;
    }
    return ans;
  }

	public static long div(long x, long y){
		return (x*pow(y, mod-2))%mod;
	}

  //fac, inv, finvテーブルの初期化、これ使う場合はinitComb()で初期化必要
	public static  void initComb(){
		fac[0] = finv[0] = inv[0] = fac[1] = finv[1] = inv[1] = 1;
		for (int i = 2; i < size; ++i) {
			fac[i] = fac[i - 1] * i % mod;
			inv[i] = mod - (mod / i) * inv[(int) (mod % i)] % mod;
			finv[i] = finv[i - 1] * inv[i] % mod;
		}
	}

	//nCk % mod
	public static long comb(int n, int k){
		return fac[n] * finv[k] % mod * finv[n - k] % mod;
	}

	//n! % mod
	public static long fact(int n){
		return fac[n];
	}

	//(n!)^-1 with % mod
	public static long finv(int n){
		return finv[n];
	}

  static class UnionFind {
    int[] parent;
    public UnionFind(int size) {
      parent = new int[size];
      Arrays.fill(parent, -1);
    }
    public boolean unite(int x, int y) {
      x = root(x);
      y = root(y);
      if (x != y) {
        if (parent[y] < parent[x]) {
          int tmp = y;
          y = x;
          x = tmp;
        }
        parent[x] += parent[y];
        parent[y] = x;
        return true;
      }
      return false;
    }
    public boolean same(int x, int y) {
      return root(x) == root(y);
    }
    public int root(int x) {
      return parent[x] < 0 ? x : (parent[x] = root(parent[x]));
    }
    public int size(int x) {
      return -parent[root(x)];
    }
  }
	public static int upperBound(long[] array, long value) {
			 int low = 0;
			 int high = array.length;
			 int mid;
			 while( low < high ) {
					 mid = ((high - low) >>> 1) + low; // (high + low) / 2
					 if( array[mid] <= value ) {
							 low = mid + 1;
					 } else {
							 high = mid;
					 }
			 }
			 return low;
	 }
	 public static final int lowerBound(final long[] arr, final long value) {
    int low = 0;
    int high = arr.length;
    int mid;
    while (low < high) {
        mid = ((high - low) >>> 1) + low;    //(low + high) / 2 (オーバーフロー対策)
        if (arr[mid] < value) {
            low = mid + 1;
        } else {
            high = mid;
        }
    }
    return low;
}
  //n,mの最大公約数
  public static long gcd(long n, long m){
    if(m > n) return gcd(m,n);
    if(m == 0) return n;
    return gcd(m, n%m);
  }
	//3要素のソート
	private class Pair2 implements Comparable<Pair2> {
		String s;
		int p;
		int index;
		public Pair2(String s, int p, int index) {
				this.s = s;
				this.p = p;
				this.index = index;
		}

		public int compareTo(Pair2 other) {
				if (s.equals(other.s)) {
						return other.p - this.p;
				}
				return this.s.compareTo(other.s);
		}
	}
	//c -> intに変換
public static long c2i(char c){
	if('A' <= c && c <= 'Z'){
		return c - 'A';
	}else{
		return c - 'a' + 26;
	}
}
// int -> toに変換
public static char i2c(long i){
	if(0 <= i && i < 26){
			return (char)(i + 'A');
	}else{
			return (char)(i + 'a' - 26);
	}
}

}
