Mortgage interest in a multifamily I live in - enter full amount in income and deduction?

Hi, I live in a multifamily with one rental apartment.  In the Wages & Income section there are instructions to enter the full amount in box 1 of the 1098.  Then in deductions, it seems like I'm to enter the full amount again, but not for rental properties.  Can you clarify, assuming the rental apartment is 50% of the dwelling, how much I should enter in each case?  Thanks!