1295. Round Down to Nearest Power of Two

Given a non-negative integer n, return the largest power of two that is less than or equal to n (that is, keep only the highest set bit). If n is 0 there is no such power, so return 0.

Input: A JSON object {"n": <non-negative integer>}.

Output: Return the largest power of two <= n, or 0 when n is 0.

Examples

Input: {"n":19}
Output: 16
Explanation: The highest power of two not exceeding 19 is 16.

Input: {"n":16}
Output: 16
Explanation: 16 is already a power of two, so it rounds down to itself.

Constraints

• 0 <= n <= 10^15

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