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.BufferedReader;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
    final static long MOD = 1000000007;

    public static void main(String args[]) {
        FastScanner fs = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
        int n = fs.nextInt();
        out.println(n % 2 != 0 ? 0 : (long) Math.pow(2, (n/2.0)));
        out.flush();
        out.close();
    }

    static class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        public FastScanner() {
            try {
                br = new BufferedReader(new InputStreamReader(System.in));
                //                br = new BufferedReader(new FileReader("file2.txt"));
                st = new StringTokenizer("");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public String next() {
            if (st.hasMoreTokens())
                return st.nextToken();
            try {
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                e.printStackTrace();
            }
            return st.nextToken();
        }

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

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

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

        public String nextLine() {
            String line = "";
            try {
                line = br.readLine();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return line;
        }

        public char nextChar() {
            return next().charAt(0);
        }

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

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

        public long[] nextLongArray(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }

        public char[] nextCharArray() {
            return nextLine().toCharArray();
        }
    }

}


