When—

(A) one or more persons were entitled (without the application of section 402(j)(1) of this title ) to monthly benefits under section 402 of this title for May 1978 on the basis of the wages and self-employment income of an individual,

(B) the benefit of at least one such person for June 1978 is increased by reason of the amendments made by section 204 of the Social Security Amendments of 1977; and

(C) the total amount of benefits to which all such persons are entitled under such section 402 of this title are reduced under the provisions of this subsection (or would be so reduced except for the first sentence of subsection (a)(4)),

then the amount of the benefit to which each such person is entitled for months after May 1978 shall be increased (after such reductions are made under this subsection) to the amount such benefits would have been if the benefit of the person or persons referred to in subparagraph (B) had not been so increased.