The following transactions or events occurred between 2013 and 2018 in Furong Company: (1) An office building for management was purchased on December 31, 2013, and the actual acquisition cost was RMB 600 million. The estimated service life of the office building is 30 years, and the estimated net residual value is zero. Depreciation is calculated using the average life method. (2) Due to the company's relocation, Furong and Shijing signed a lease agreement on June 20, 2016. The agreement stipulates: Furong Company leased the above office buildings to Ishii Company by operating lease. The lease period starts on June 30, 2016, the lease period is 2 years, and the annual rent is 30 million yuan, paid once every six months. The fair value of the office building was 560 million yuan at the beginning of the lease period. The office building had no provision for impairment until June 30, 2016. (3) Furong Company uses the fair value model for subsequent measurement of investment real estate. On December 31, 2016, the fair value of the office building was 440 million yuan; on December 31, 2017, the fair value of the office building was 420 million yuan; on June 30, 2018, the lease period expired, Furong Company will The investment real estate is directly sold to the outside world after being recovered, and the selling price is 40 million yuan. Assuming that the relevant taxes and fees are not considered, the requirements are: (1) Determine the conversion date of investment real estate; (2) Calculate the depreciation amount that Furong Company should accrue in the office building in 2016; (3) Preparation of accounting entries for the start date of the lease period; (4) Compile the accounting entries of Furong Company in 2016 when it obtains rental income; (5) Compile the accounting entry of Furong Company's sale of investment real estate on June 30, 2018.