system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
"""
EXHIBIT 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that the statement on Schedule 13G with respect to the equity securities of Q Biomed, Inc. is, and any amendment thereto signed by each of the undersigned shall be, filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended. The undersigned hereby further agree that this Joint Filing Agreement be included as an exhibit to such statement and any such amendment. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained herein and therein, but shall not be responsible for the completeness and accuracy of the information concerning the others. This Joint Filing Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument. Dated: 4/8/2020 YA II PN, Ltd. By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer YA Global Investments II (U.S.), Ltd. By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer Yorkville Advisors Global, LP By:Yorkville Advisors Global, LLC Its:General Partner By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer Yorkville Advisors Global II, LLC By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer YAII GP, LP By:Yorkville Advisors GP, LLC Its:General Partner By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer Yorkville Advisors GP, LLC By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer D-Beta One EQ, Ltd. By:Delta Beta Advisors, LLC Its:Investment Manager By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer D-Beta One Blocker EQ, Ltd. By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer D-Beta One Growth and Opportunity Fund Offshore, LP By:D-Beta One GP, LP Its:General Partner By:D-Beta One GP, LLC Its:General Partner By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer D-Beta One GP, LLC By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer Delta Beta Advisors, LP By:Delta Beta Advisors, LLC Its:General Partner By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer D-Beta One GP, LLC By:/s/ Troy J. Rillo, Esq. Date: 4/8/2020 Troy J. Rillo, Esq. Chief Compliance Officer /s/ Matthew Beckman Date: 4/8/2020 Matthew Beckman
"""

Extract the exact clause related to "Rofr/Rofo/Rofn" from the excerpt above.

assistant: Not found.