Home Office Deduction: For depreciation I know the "Cost of Entire Home" is price I paid at closing, but how do I determine "Cost of Land (if any is included above)".

I worked as an employee of a company that was located over 2800 miles away so I was only classified as a teleworker. I bought a new home with an office that was exclusive and dedicated to my work as an employee. I'm calculating the home office expenses and am now looking at the depreciation section. I know the closing cost of the home but don't know where to find out the cost of the land included in that home cost.