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.
/*package whatever //do not write package name here */

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

public class Codeforce {
	public static void main (String[] args) {
	    FastReader fr = new FastReader();
	    int n =  fr.nextInt();
	    if(n%2 != 0) {
	        System.out.println("0");
	    }else{
	        int x = n/2;
	        long ans = (long)Math.pow(2, x);
	        System.out.println(ans);
	    }
    }
}
class FastReader {
 
    BufferedReader bf;
    StringTokenizer st;
 
    public FastReader() {
        bf = new BufferedReader(new InputStreamReader(System.in));
    }
 
    String next() {
        while (st == null || !st.hasMoreElements()) {
            try {
                st = new StringTokenizer(bf.readLine());
            } catch (Exception e) {
                System.out.println(e);
            }
        }
        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 = bf.readLine();
        } catch (Exception e) {
            System.out.println(e);
        }
        return str;
    }
}