You are given an integer $C$ such that the XOR of two integers $(A, B)$ is $C$. In short $A ⊕ B = C$ (⊕ denotes the bitwise the XOR operation).

Out of all possible pairs of $A$ and $B$, you must find two integers such that their product is maximum. 

Let us define $L(A)$ as the length of $A$ in its binary representation. Then, $L(A) \le L(C)$ and $L(B) \le L(C)$.

Input format 

A single integer representing $C$ ($0⩽C⩽10^5$)

Output format 

Print the maximum product you can achieve under the given conditions.