I have a loan on my primary home that i acquired in 2015 <500k , i bought another home at end of 2018 with a balance of $1.1 mill, how to calc adj amount from 1098

the first home was converted from primary to rental property at the same time when i purchased this home, i received 2 1098's and wondering how to calculate adjusted mortgage interest given that this loan was 1.1mill (although only for 2 months in 2018) 

the other home(<500k) was primary for 10 months