# Solving Leetcode Interviews in Seconds with AI: Smallest Number With All Set Bits


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "3370" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like [Chatmagic](https://www.chatmagic.app), we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

	# Problem Statement
	> You are given a positive number n. Return the smallest number x greater than or equal to n, such that the binary representation of x contains only set bits   Example 1:  Input: n = 5 Output: 7 Explanation: The binary representation of 7 is "111".  Example 2:  Input: n = 10 Output: 15 Explanation: The binary representation of 15 is "1111".  Example 3:  Input: n = 3 Output: 3 Explanation: The binary representation of 3 is "11".    Constraints:  1 <= n <= 1000  

	# Explanation
	Here's the breakdown of the solution:

*   **Find the Most Significant Bit:** Determine the position of the most significant bit (MSB) in the binary representation of the input number *n*.
*   **Create a Mask:** Construct a number that has all bits set from the least significant bit up to the MSB position. This effectively creates a number with all 1s in its binary representation up to the required length.
*   **Return the Mask:** The mask itself is the smallest number greater than or equal to *n* with all set bits.

*   **Runtime Complexity:** O(log n) - due to finding the MSB. **Storage Complexity:** O(1) - constant extra space.

	
	# Code
	```python
	def solve():
    n = int(input())

    msb = 0
    temp = n
    while temp > 0:
        temp >>= 1
        msb += 1

    result = (1 << msb) - 1
    print(result)

solve()
	```