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:
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will furnish to you, at your Restaurant and at our expense, one (1) or more of our representatives for the purpose of training your employees and management team in the operation of a Franchised Restaurant. During this period, the representatives will assist in establishing and standardizing procedures and techniques essential to the operation of a Buffalo Wild Wings business. If you request additional assistance from us in order to facilitate the opening of the Franchised Restaurant, and if, we, in our discretion, deem it necessary, feasible and appropriate to comply with the request, you will reimburse us for our expenses in providing such additional assistance, which may include our then-current service fee. You agree that during the week preceding the opening, you will have four (4) full days during which the Restaurant is fully operational and will host two (2) opening parties. D. If we determine, in our sole discretion, that you or your manager is unable to satisfactorily complete the required training program, you will have thirty (30) days to provide an alternate person to complete the training program at your sole expense. At least three (3) persons actively involved in the management and operation of the Franchised Restaurant must successfully complete the training program. If you fail to provide three (3) persons who can complete the training program, we will have the right to terminate this Agreement and you will not be entitled to a refund of any portion of the franchise fees paid. E. From time to time we may provide and if we do, may require that previously-trained and experienced franchisees, their managers and/or employees attend and successfully complete refresher training programs or seminars to be conducted at our training facility or at such other place as we shall designate. Attendance at such refresher training programs or seminars will be at your sole expense, provided, however, that attendance will not be required at more than two (2) such programs in any calendar year. 5 V. PROPRIETARY MARKS A. You acknowledge that our parent company is the owner of all right, title and interest together with all the goodwill of the Marks and has licensed the use of such Marks to us with the right to sublicense others. You further acknowledge that your right to use the Marks is derived solely from this Agreement and is limited to the conduct of business by you pursuant to and in compliance with this Agreement and all applicable standards, specifications, and operating procedures prescribed by us from time to time during the term of the Agreement. Any unauthorized use of the Marks by you is a breach of this Agreement and an infringement of the rights of us in and to the Marks. You acknowledge that your usage of the Marks and any goodwill established by your use of the Marks shall inure to the exclusive benefit of us and our affiliate, and that this Agreement does not confer any goodwill or other interests in the Marks upon you. Any developments and improvements by you relating to the Marks or the System shall be our sole property. You will not, at any time during the term of this Agreement or after its termination or expiration, contest the validity or ownership of any of the Marks or assist any other person in contesting the validity or ownership of the Marks. All provisions of this Agreement applicable to the Marks apply to any and all additional trademarks, service marks, and commercial symbols authorized for use by and licensed to you by us after the date of this Agreement. B. You will not use any Mark or portion of any Mark as part of a corporate or trade name, or with any prefix, suffix, or other modifying words, terms, designs, or symbols, or in any modified form. You will not use any Mark in connection with the sale of any unauthorized product or service or in any other manner not expressly authorized in writing by us. You shall give such notices of trademark and service mark registrations as we specify and to obtain such fictitious or assumed name registrations as may be required under applicable law. Your use of any of the Marks on the Internet/World Wide Web (including any Home Page) or any other medium must have our prior written approval. We reserve the right to prohibit your use of the Marks on the Internet. C. You will promptly notify us of any claim, demand or cause of action based upon or
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Extract the exact clause related to "Covenant Not To Sue" from the excerpt above.

assistant: You will not, at any time during the term of this Agreement or after its termination or expiration, contest the validity or ownership of any of the Marks or assist any other person in contesting the validity or ownership of the Marks.