You have a given integer n. Find the number of ways to fill all 3 × n tiles with the shape described in the picture below. Upon filling, no empty spaces are allowed. Shapes cannot overlap.

<image> This picture describes when n = 4. The left one is the shape and the right one is 3 × n tiles. 

Input

The only line contains one integer n (1 ≤ n ≤ 60) — the length.

Output

Print the number of ways to fill.

Examples

Input


4


Output


4

Input


1


Output


0

Note

In the first example, there are 4 possible cases of filling.

In the second example, you cannot fill the shapes in 3 × 1 tiles.
import java.io.*;
import java.util.*;
import java.math.*;
import java.math.BigInteger;
public final class codeForces
{    
    static StringBuilder ans=new StringBuilder();;
    static FastReader in=new FastReader();
    static ArrayList<ArrayList<Integer>> g=new ArrayList<ArrayList<Integer>>();
    static int max=0;

    static boolean set[];
    public static void main(String args[])
    {
        int N=in.nextInt();
        if((N&1)==0)
        {
            System.out.println(1<<(N>>1));
        }
        else System.out.println(0);
    }

    static void DFS(int N,int d)
    {
        set[N]=true;
        d++;
        max=Math.max(max,d);
        for(int i=0; i<g.get(N).size(); i++)
        {
            int c=g.get(N).get(i);
            if(set[c]==false)
            {
                DFS(c,d);
            }
        }
    }

    static int countBits(long a)
    {
        return (int)(Math.log(a)/Math.log(2)+1);
    }
    //fucntions
    //fucntions
    //fucntions
    //fucntions
    static int[] input(int A[]) //input of Int Array
    {
        FastReader in=new FastReader();
        int N=A.length;
        for(int i=0; i<N; i++)
        {
            A[i]=in.nextInt();
        }
        return A;
    }

    static long[] input(long A[]) //Input of long Array
    {
        FastReader in=new FastReader();
        for(int i=0; i<A.length; i++)A[i]=in.nextLong();
        return A;
    }

    static int GCD(int a,int b) //wrong output if a ||b are intially zero
    {
        if(b==0)
        {
            return a;
        }
        else return GCD(b,a%b );
    }

    static boolean isPrime(int N)
    {
        for(int i=2; i*i<N; i++)
            if(N%i==0)return false;
        return true;
    }

}
//Code For FastReader
//Code For FastReader
//Code For FastReader
//Code For FastReader
class FastReader
{
    BufferedReader br;
    StringTokenizer st;
    public FastReader()
    {
        br=new BufferedReader(new InputStreamReader(System.in));
    }

    String next()
    {
        while(st==null || !st.hasMoreElements())
        {
            try
            {
                st=new StringTokenizer(br.readLine());
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }

    int nextInt()
    {
        return Integer.parseInt(next());
    }

    long nextLong()
    {
        return Long.parseLong(next());
    }

    double nextDouble()
    {
        return Double.parseDouble(next());
    }

    String nextLine()
    {
        String str="";
        try
        {
            str=br.readLine();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return str;
    }

}