1. All appeals by the Defendants are dismissed.

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

3. Text of the judgment of the court of first instance;

1. The reasons for the acceptance of the judgment of the court of first instance are as follows, i.e., the reasons for the reversal of the judgment of the court of first instance, i.e., the reasons for the second instance except for the second instance judgment.

[However, it is called "B" as a joint defendant corporation B (hereinafter referred to as "B") in the first instance court which is separated and determined.

(2) Part 5 of the first instance court's decision No. 4 to 6 of the first instance court's decision No. 5 of the first instance court's decision is reversed as follows.

(b) After a debtor becomes aware that a creditor of the right of subrogation exercises his right by subrogation, even though he disposes of such right, it cannot be set up against the creditor.

(see Article 405(2) of the Civil Act). This prohibition is prohibited since it prevents a creditor from exercising the right of subrogation, if the creditor notifies the debtor of the fact of exercising the right of subrogation, or the debtor allows the debtor to take a disposition, such as transfer or waiver of the right of subrogation, which is the object of subrogation, after

(See Supreme Court en banc Decision 2011Da87235 Decided May 17, 2012). Therefore, in a case where a third-party obligor’s disposal is an act of disposal in form, but its substance is the case where the obligor is pretended to oppose the subrogation obligee on behalf of himself/herself or the third-party obligor, or where the obligor and the third-party obligor agree or agree with each other, the third-party obligor shall be deemed to have disposed of the subrogated claim, and thus, the third-party obligor cannot oppose the obligee who exercises the subrogation right.

However, in full view of the facts without any dispute, and the purport of the entire pleadings in the statements in subparagraphs 1 through 3, the Plaintiff filed the instant lawsuit against the Defendants, B, etc. on June 7, 2018, and thereafter, from January 31, 2019 to February 1, 2019, the Defendants reached an agreement with B as to the instant construction work.