conversations.from: human
conversations.value: Solve the math problem: Michael has $42. Michael gives away half the money to his brother. His brother then buys 3 dollars worth of candy. If his brother has $35 left, how much money, in dollars, did his brother have at first?
conversations.from: assistant
conversations.value: Michael gives away 42/2=21 dollars.
  Before buying candy, his brother has 35+3=38 dollars.
  His brother had 38-21=17 dollars at first.