All appeals are dismissed.

The costs of appeal between the Plaintiff and the Defendant are assessed against each other, and the Plaintiff.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. On the grounds of appeal by the plaintiff and the defendant, the court below held that the defendant had the authority to possess each of the buildings of this case as the lien holder before the defendant was paid 683,120,551 won for the second construction work price in full from E, and rejected each of the claims for the termination of the plaintiff's right to retention, the defendant occupied and used each of the buildings of this case during the F's ownership holding period, thereby gaining profits of 567,626,447 won as stated in its judgment, and the remainder except for KRW 100 million returned to F was appropriated to repay the claim for the second construction work price, and as a result, the court below held that the defendant had the authority to retain the building of this case until the expiration of the prescription period of the plaintiff's right to retention and the claims for termination of the right to retention.

In light of the records, the above determination by the court below is just, and it did not err in the misapprehension of legal principles as to the party to an exchange contract, the existence of a claim for construction price, the grounds for extinguishment of a right of retention beyond the bounds of the principle of free evaluation of evidence against logical and empirical rules, as alleged in the plaintiff's grounds of appeal, or in the misapprehension of legal principles as to the establishment time of the secured claim of a right of retention and the due date, the "other person" of an object which is one of the elements for establishment of a right of retention, the claim for extinguishment of a right of retention, the extinctive prescription, and the appropriation of the profits from possession within the ownership holding period of K, and it violated