You are given a number N. Find the total number of setbits in the numbers from 1 to N.
Example 1:
Input: N = 3
Output: 4
Explaination:
1 -> 01, 2 -> 10 and 3 -> 11.
So total 4 setbits.
Example 2:
Input: N = 4
Output: 5
Explaination: 1 -> 01, 2 -> 10, 3 -> 11
and 4 -> 100. So total 5 setbits.
Your Task:
You do not need to read input or print anything. Your task is to complete the function countBits() which takes N as input parameter and returns the total number of setbits upto N.
Expected Time Complexity: O(1)
Expected Auxiliary Space: O(1)
Constraints:
1 ≤ N ≤ 10^{9}

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