Magnificent Mining Company constructed a building costing P3,920,000 on the mine property. Its estimated residual value will not benefit the company and will be ignored for purposes of computing depreciation. The building has an estimated life of 10 years. The total estimated recoverable units from the mine is 700,000 tons. The company's production of the first four years of operations was:

First year 140,000 tons

Second year 140,000 tons

Third year Shut down, no output

Fourth year 140,000 tons

What is the depreciation for the fourth year?