code: func UnsignedBitsRequired(bits int64) int {
  	if bits == 0 {
  		return 1
  	}
  	n := uint64(bits)
  	ans := 0
  	for n != 0 {
  		n >>= 1
  		ans++
  	}
  	return ans
  }
docs: /*
  Returns how many bits are required to store bits, interpreted as an
  unsigned value.
  NOTE: This method returns at least 1.
  */