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.*;

public class A {

    void solve() {
        int n = in.nextInt();
        if (n % 2 != 0) {
            out.println(0);
            return;
        }
        
        out.println(1L << (n/2));
    }
    

    Scanner in;
    PrintWriter out;

    void run() {
        try {
            in = new Scanner(new File("A.in"));
            out = new PrintWriter(new File("A.out"));

            solve();

            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    void runIO() {

        in = new Scanner(System.in);
        out = new PrintWriter(System.out);

        solve();

        out.close();
    }

    class Scanner {
        BufferedReader br;
        StringTokenizer st;

        public Scanner(File f) {
            try {
                br = new BufferedReader(new FileReader(f));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }

        public Scanner(InputStream f) {
            br = new BufferedReader(new InputStreamReader(f));
        }

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

        private boolean isSpaceChar(int c) {
            return !(c >= 33 && c <= 126);
        }

        private int skip() {
            int b;
            while ((b = read()) != -1 && isSpaceChar(b)) ;
            return b;
        }

        private int read() {
            int res = -1;
            try {
                res = br.read();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return res;
        }

        char[] nextCharArray(int size) {
            char[] buf = new char[size];
            int b = skip(), p = 0;
            while (p < size && !(isSpaceChar(b))) {
                buf[p++] = (char) b;
                b = read();
            }
            return size == p ? buf : Arrays.copyOf(buf, p);
        }

        char[][] nextCharMap(int n, int m) {
            char[][] map = new char[n][];
            for (int i = 0; i < n; i++) {
                map[i] = nextCharArray(m);
            }
            return map;
        }

        int[] na(int n) {
            int[] arr = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = in.nextInt();
            }
            return arr;
        }

        boolean hasMoreTokens() {
            while (st == null || !st.hasMoreTokens()) {
                String s = null;
                try {
                    s = br.readLine();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (s == null)
                    return false;
                st = new StringTokenizer(s);
            }
            return true;
        }

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

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

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

    public static void main(String[] args) {
        new A().runIO();
    }
}