1. The plaintiffs' appeal is dismissed.

2. The costs of appeal are assessed against the Plaintiffs.

The purport of the claim and appeal is the purport of the appeal.

1. The reasoning of the judgment of the court of first instance cited in the judgment of this court is as follows: (a) 5th 17th e of the judgment of the court of first instance (“Defendant A”; (b) 5th eth 19th eth eth eth 19th eth eth eth eth eth eth eth eth eth eth eth eth eth eth eth eth 8th eth eth eth eth eth eth eth eth eth eth eth 8th eth eth eth eth 6th eth eth eth eth eth eth 18th eth eth eth eth eth eth eth eth eth eth eth eth 19th eth eth eth eth eth eth eth e)

2. Additional determination

A. The plaintiffs asserted that the defendant's voluntary revision of the agreement of this case was erroneous in the defendant's arbitrary revision of the agreement of this case submitted by the defendant (No. 6-1 of the evidence No. 6), but the defendant's evidence submitted by the plaintiff (Evidence No. 15 of the evidence No. 15) cannot be accepted.

B. The plaintiffs asserted that there is no cause for payment of penalty under Article 9(2) of the instant agreement, and D made best efforts so that they may receive a contract for civil engineering works as appropriate construction cost pursuant to the instant agreement. The defendant's failure to conclude a contract for civil engineering works among the new construction works of Etel at the time of acceptance by the defendant is entirely attributable to the defendant, i.e., that is, because the defendant presented an excessive high-quality subcontract construction cost in the bidding process, it cannot be deemed that the cause for payment of penalty under the instant agreement has occurred. Thus, the defendant's assertion based on the premise that the occurrence of penalty and the amount paid by the plaintiff A was appropriated for penalty, is without merit, but even if each evidence submitted by the first instance court was presented to the court, the defendant's assertion is