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.util.*;
import java.io.*;
 
public class A {
 
    public static void main(String[] args) throws Exception {
        // FileInputStream inputStream = new FileInputStream("input.txt");
        // FileOutputStream outputStream = new FileOutputStream("output.txt");
 
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
         
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
 
        Solver solver = new Solver();     
        // int t = in.nextInt();
        // for (int i = 0 ; i < t ; i++) {
            solver.solve(1, in, out);
        // }
                 
        out.close();
    }
 
    static class Solver {
 
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            long n = in.nextLong();
            if (n % 2 == 1) out.println(0); else {
                n /= 2;
                out.println((long)Math.pow(2, n));
            }
        }
    }
             
 
    static class InputReader {
 
        public BufferedReader reader;
        public StringTokenizer tokenizer;
 
        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }
 
        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
 
        public int nextInt() {
            return Integer.parseInt(next());
        }
 
        public long nextLong() {
            return Long.parseLong(next());
        }
 
        public double nextDouble() {
            return Double.parseDouble(next());
        }
 
        public float nextFloat() {
            return Float.parseFloat(next());
        }
    }
}