50 employees of a single component of the Department of Homeland Security, who are stationed in the United States, at a single international conference unless the Secretary of Homeland Security, or a designee, determines that such attendance is in the national interest and notifies the Committees on Appropriations of the Senate and the House of Representatives within at least 10 days of that determination and the basis for that determination: Provided , That for purposes of this section the term international conference shall mean a conference occurring outside of the United States attended by representatives of the United States Government and of foreign governments, international organizations, or nongovernmental organizations: Provided further , That the total cost to the Department of Homeland Security of any such conference shall not exceed $500,000. 526. None of the funds made available in this Act may be used to reimburse any Federal department or agency for its participation in a National Special Security Event. 527. None of the funds made available to the Department of Homeland Security by this or any other Act may be obligated for any structural pay reform that affects more than 100 full-time positions or costs more than $5,000,000 in a single year before the end of the 30-day period beginning on the date on which the Secretary of Homeland Security submits to Congress a notification that includes— (1) the number of full-time positions affected by such change