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.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution 
{
	static class InputReader
	{
	    private final InputStream stream;
	    private final byte[] buf = new byte[8192];
	    private int curChar, snumChars;

	    public InputReader(InputStream st) {
	      this.stream = st;
	    }

	    public int read() {
	      if (snumChars == -1)
	        throw new InputMismatchException();
	      if (curChar >= snumChars) {
	        curChar = 0;
	        try {
	          snumChars = stream.read(buf);
	        } catch (IOException e) {
	          throw new InputMismatchException();
	        }
	        if (snumChars <= 0)
	          return -1;
	      }
	      return buf[curChar++];
	    }

	    public int nextInt() {
	      int c = read();
	      while (isSpaceChar(c)) {
	        c = read();
	      }
	      int sgn = 1;
	      if (c == '-') {
	        sgn = -1;
	        c = read();
	      }
	      int res = 0;
	      do {
	        res *= 10;
	        res += c - '0';
	        c = read();
	      } while (!isSpaceChar(c));
	      return res * sgn;
	    }

	    public long nextLong() {
	      int c = read();
	      while (isSpaceChar(c)) {
	        c = read();
	      }
	      int sgn = 1;
	      if (c == '-') {
	        sgn = -1;
	        c = read();
	      }
	      long res = 0;
	      do {
	        res *= 10;
	        res += c - '0';
	        c = read();
	      } while (!isSpaceChar(c));
	      return res * sgn;
	    }

	    public int[] nextIntArray(int n) {
	      int a[] = new int[n];
	      for (int i = 0; i < n; i++) {
	        a[i] = nextInt();
	      }
	      return a;
	    }

	    public String readString() {
	      int c = read();
	      while (isSpaceChar(c)) {
	        c = read();
	      }
	      StringBuilder res = new StringBuilder();
	      do {
	        res.appendCodePoint(c);
	        c = read();
	      } while (!isSpaceChar(c));
	      return res.toString();
	    }

	    public String nextLine() {
	      int c = read();
	      while (isSpaceChar(c))
	        c = read();
	      StringBuilder res = new StringBuilder();
	      do {
	        res.appendCodePoint(c);
	        c = read();
	      } while (!isEndOfLine(c));
	      return res.toString();
	    }

	    public boolean isSpaceChar(int c) {
	      return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	    }

	    private boolean isEndOfLine(int c) {
	      return c == '\n' || c == '\r' || c == -1;
	    }
	}
   	public static class pair implements Comparable<pair>
    {
        int first;
        int second;
        public pair(int a,int b)
        {
            this.first = a;
            this.second = b;
        }
        public int compareTo(pair u)
        {
            return (u.first - u.second) - (first - second);
        }
    }
    public static long gcd(long a,long b)
    {
        if(b == 0)
            return a;
        return gcd(b,a%b);
    }
    public static ArrayList<Integer> sieve(int[] lps,int n)
	{
		ArrayList<Integer> arr = new ArrayList<>();
		for(int i = 2;i <= n;i++)
		{
			if(lps[i] == 0)
			{
				lps[i] = i;
				arr.add(i);
			}
			for(int j = 0;j < arr.size() && arr.get(j) <= lps[i] && i*arr.get(j) <= n;j++)
				lps[i*arr.get(j)] = arr.get(j);
		}
		return arr;
	}
 	public static void main(String[] args) throws IOException 
    {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(System.out);
        int n = Integer.parseInt(br.readLine());
        if(n % 2 != 0)
            out.println("0");
        else 
        {
            long t = (long)(n/2);
            long ans = (long)Math.pow(2, t);
            out.println(ans);
        }
        out.close();
    }
}
