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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be accepted as the base of a claim. The Sellers, in accordance with the Buyers' claim, shall be responsible for the immediate elimination of the defect(s), complete or partial replacement of the commodity or shall devaluate the commodity according to the state of defect(s). Where necessary, the Buyers shall be at liberty to eliminate the defect(s) themselves at the Sellers' expenses. If the Sellers fail to answer the Buyers within one weeks after receipt of the aforesaid claim, the claim shall be reckoned as having been accepted by the Sellers. 4 Source: LOHA CO. LTD., F-1, 12/9/2019 17. FORCE MAJEURE: The Sellers shall not be held responsible for the delay in shipment or non-delivery, of the goods due to Force Majeure, which might occur during the process of manufacturing or in the course of loading or transit. The Sellers shall advise the Buyers immediately of the occurrence mentioned above and within fourteen days thereafter, the Sellers shall send by airmail to the Buyers a certificate of the accident issued by the competent government authorities, Chamber of Commerce or registered notary public of the place where the accident occurs as evidence thereof. Under such circumstances the Sellers, however, are still under the obligation to take all necessary measures to hasten the delivery of the goods. In case the accident lasts for more than 10 weeks, the Buyers shall have the right to cancel the Contract. 18. LATE DELIVERY AND PENALTY: Should the Sellers fail to make delivery on time as stipulated in the Contract, with exception of Force Majeure causes specified in Clause 17 of this Contract, the Buyers shall agree to postpone the delivery on condition that the Sellers agree to pay a penalty which shall be deducted by the paying bank from the payment. The penalty, however, shall not exceed 5% of the total value of the goods involved in the late delivery. The rate of penalty is charged at 0.5% for every seven days, odd days less than seven days should be counted as seven days. In case the Sellers fail to make delivery ten weeks later than the time of shipment stipulated in the Contract, the Buyers have the right to cancel the contract and the Sellers, in spite of the cancellation, shall still pay the aforesaid penalty to the Buyers without delay, the seller should refund the money received and pay the 30% of the total goods price of the penalty 19. ARBITRATION: All disputes in connection with this Contract or the execution thereof shall be settled friendly through negotiations. In case no settlement can be reached, the case may then be submitted for arbitration to the Foreign Economic and Trade Arbitration Committee of the China Beijing Council for the Promotion of International Trade in accordance with its Provisional Rules of Procedures by the said Arbitration Committee. The Arbitration shall take place in Beijing and the decision of the Arbitration Committee shall be final and binding upon both parties; neither party shall seek recourse to a law court nor other authorities to appeal for revision of the decision. Arbitration fee shall be borne by the losing party. 20. This final price is the confidential information. Dissemination, distribution or duplication of this price is strictly prohibited. 5 Source: LOHA CO. LTD., F-1, 12/9/2019 21. Law application It will be governed by the law of the People's Republic of China ,otherwise it is governed by United Nations Convention on Contract for the International Sale of Goods. 22. <<Incoterms 2000>> The terms in the contract are based on (INCOTERMS 2000) of the International Chamber of Commerce. 23. The Contract is valid for 5 years, beginning from and ended on . This Contract is made out in three originals in both Chinese and English, each language being legally of the equal effect. Conflicts between these two languages arising there from, if any, shall be subject to Chinese version. One copy for the Sellers, two copies for the Buyers. The Contract becomes effective after signed by both parties. THE BUYER: THE SELLER: SIGNATURE: SIGNATURE: 6 Source: LOHA CO. LTD., F-1, 12/9/2019
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Extract the exact clause related to "Ip Ownership Assignment" from the excerpt above.