Adjustment in deduction for personal exemption

In the case of a taxpayer other than a corporation, if a return is made for a short period by reason of subsection (a)(1) and if the tax is not computed under subsection (b)(2), then the exemptions allowed as a deduction under section 151 (and any deduction in lieu thereof) shall be reduced to amounts which bear the same ratio to the full exemptions as the number of months in the short period bears to 12.