; and (B) decreased by the difference obtained by subtracting the amount of primary budget authority provided for a fiscal year from the adjusted spending ceiling (excluding any adjustment under section 444(1), and including the effect of adjustments under section 445(c)) for that fiscal year. (2) Limit of zero The amount of the emergency account may not be less than $0. (c) Adjustment (1) In general If the amount of the emergency account on the last day of a fiscal year has increased, as compared to the last day of the fiscal year before such fiscal year, the amount of the spending ceiling for the second fiscal year after such fiscal year and each of the ensuing 5 fiscal years shall be reduced by the amount equal to one-sixth of the amount of the increase in the emergency account. (2) Modification of adjustment (A) For congressional purposes When adopting a concurrent resolution on the budget (including a concurrent resolution on the budget described in section 304), Congress may, for purposes of applying the spending ceiling in the Senate and the House of Representatives— (i) reduce the amount of the spending ceiling by the amount of the emergency account over a period shorter than 6 fiscal years; or (ii) in the case of an ongoing emergency, reduce the amount of the spending ceiling by the amount of the emergency account over a period longer than 6 fiscal years. (B) For executive branch purposes When enacting a supplemental appropriations Act, Congress may, for purposes of applying the spending ceiling in the executive branch— (i) reduce the amount of the spending ceiling by the amount of the emergency account over a period shorter than 6 fiscal years