#824. Tower of Hanoi: number of moves
Find the smallest number of moves needed to move a Tower of Hanoi with n disks.
### Input
n (1 ≤ n ≤ 60).
### Output
Answer.
Examples
Input
1
Output
1
Input
46
Output
70368744177663
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.