1. The Defendant’s KRW 229,357,552 to the Plaintiffs and KRW 200,000 among them, and KRW 29,357,452 to the Plaintiffs.

1. Facts of recognition;

A. (1) The Defendant entered into the instant construction contract, etc.) on February 11, 2014, the Plaintiffs and C Co., Ltd. (hereinafter “C”).

As between the corporation and the corporation, the “E Corporation” (hereinafter referred to as the “instant Corporation”).

() As to the total construction period, 730 days from the commencement date of the construction project (from February 19, 2014 to February 18, 2016), the construction contract for a long-term continuing construction project, the total construction price of which is KRW 16,937,948,500, is collectively referred to as the “instant construction contract.” The instant construction contract is referred to as the “instant general contract” and the “the instant first to fourth multiple contracts” in the order of each of the following contracts.

2) Of the instant construction work, the Plaintiffs participated in the joint implementation method with respect to the type of civil engineering work (the Plaintiff A, the Plaintiff B, the share ratio of 49%), and C, with respect to the specialized fire-fighting system construction work.

[General Conditions of Construction Contract] Article 20 (Adjustment of Contract Price due to Modification of Design) (1) A contracting officer shall adjust the contract price according to the following standards if there occurs an increase or decrease in the volume of construction, such as a change in the method of construction of a design, or a change in input materials:

1. The unit price for the increased or decreased volume of construction works shall be the agreed unit price;

However, if the contractual unit price is more than the budget unit price and the quantity is increased, the applicable unit price for the increased quantity shall be the budget unit price.

2. The unit price for an item or a item without a detailed statement of particulars (including cases where performance, standard, etc. are different even for the same item; hereinafter referred to as "new item") shall be determined by the authority awarding the contract in cases where the modification of the design drawing is required at the time of the modification of design, and where the modification of the design drawing is not required, when the parties to the contract agree by the document of modification of design, and pursuant to