expressly so provided herein. 502. Subject to the requirements of section 503 of this Act, the unexpended balances of prior appropriations provided for activities in this Act may be transferred to appropriation accounts for such activities established pursuant to this Act, may be merged with funds in the applicable established accounts, and thereafter may be accounted for as one fund for the same time period as originally enacted. 503. (a) None of the funds provided by this Act, provided by previous appropriations Acts to the components in or transferred to the Department of Homeland Security that remain available for obligation or expenditure in fiscal year 2018, or provided from any accounts in the Treasury of the United States derived by the collection of fees available to the components funded by this Act, shall be available for obligation or expenditure through a reprogramming of funds that— (1) creates or eliminates a program, project, or activity, or increases funds for any program, project, or activity for which funds have been denied or restricted by the Congress