(A) If an individual is entitled to an old-age or disability insurance benefit for any month and to any other monthly insurance benefit for such month, such other insurance benefit for such month, after any reduction under subsection (q), subsection (e)(2) or (f)(2), and any reduction under section 403(a) of this title , shall be reduced, but not below zero, by an amount equal to such old-age or disability insurance benefit (after reduction under such subsection (q)).

(B) If an individual is entitled for any month to a widow’s or widower’s insurance benefit to which subsection (e)(3) or (f)(3) applies and to any other monthly insurance benefit under this section (other than an old-age insurance benefit), such other insurance benefit for such month, after any reduction under subparagraph (A) of this paragraph, any reduction under subsection (q), and any reduction under section 403(a) of this title , shall be reduced, but not below zero, by an amount equal to such widow’s or widower’s insurance benefit after any reduction or reductions under such subparagraph (A) and such section 403(a).