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.
#!/usr/bin/env python
import sys


def main():

    for line in sys.stdin:

        #n = [x for x in line.split(',')]  
    
        a  = int(line[:(len(line)-1)])
        a = a*3
        
        result =0
        if  a % 6 ==0:
            result = a/6;
            result = pow(2,result)
        
        print(int(result))
        


if __name__ == "__main__": 
    main() 
