num2 and store it in a variable setBitsNum2.x to 0.num1 from MSB to LSB:
a. If the current bit in num1 is set and setBitsNum2 is not zero, set the corresponding bit in x and decrement setBitsNum2.setBitsNum2 is still greater than zero after step 3, it means we need to set more bits in x:
a. Iterate over the bits of x from LSB to MSB.
b. For each bit that is not set in x, set it and decrement setBitsNum2 until it reaches zero.x as the result.