SDE Path

Count Numbers with Set Bit K

Medium

Count Numbers with Set Bit K

Count how many numbers from 1 to N have the Kth bit set.

Input format

A single line with N (1 ≤ N ≤ 10^5) and K (0-based bit position).

Output format

Print how many integers from 1 to N have the Kth bit set.

Constraints

  • Values fit in a 64-bit signed integer
  • Trailing whitespace and a trailing newline are ignored by the judge

Read from stdin, write to stdout. Sample cases below show the exact format.

Sample cases

Example 1
Input
10 1
Expected output
5
Example 2
Input
8 3
Expected output
1