Given the task definition and input, reply with output. 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.

alvin had 57 marbles and played 2 games . he lost 18 marbles during the first game . he won 25 marbles during the second game . how many marbles did alvin have then ?
64