Subtract Without Subtract

Create a function that subtracts one positive integer from another, without using any arithmetic operators such as -, %, /, +, etc.

Examples

mySub(5, 9) ➞ 4

mySub(10, 30) ➞ 20

mySub(0, 0) ➞ 0

Notes

• Do not multiply by -1.
• Use bitwise operations only: <<, |, ~, &, etc.