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.lang.*;
    import java.io.*;
    public class A{
        
        public static void main(String[] args){
            InputStream inputStream = System.in;
            InputReader in = new InputReader(inputStream);
            OutputStream outputStream = System.out;
            PrintWriter out = new PrintWriter(outputStream);
            Solver s = new Solver();
            s.solve(in,out);
            out.close();
        }
        static class Solver{

            private void solve(InputReader in, PrintWriter out){
                int n = in.nextInt();
                if(n%2==0){
                    int parts = n/2;
                    out.println((long)(Math.pow(2,parts)));
                }
                else{
                    out.println("0");
                }
            }   
        } 
        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 long nextLong() {
                return Long.parseLong(next());
            }
            public int nextInt() {
                return Integer.parseInt(next());
            }
        }
    }
