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.