Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.

omar loves to play checkers . he played 37 games yesterday . he played 49 games today . omar lost 18 games . how many games did he win ?
68

sean is playing monopoly with his friends . he already has 27 houses . sean traded in 8 houses for money to buy park place . he collected so much rent that he decided to buy 12 more houses . how many houses did sean have then ?
31

a pet store took 10 birds out of a cage and had 9 still left inside . how many birds were in the cage to start with ?
19