Detailed Instructions: You are given a math word problem and you are supposed to apply multiple mathematical operators like addition, subtraction, multiplication, or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
Q: the third graders are having a fair . they have 90 tickets to sell . they sold 38 tickets the first week and 17 tickets the second week . how many tickets do they have left to sell ?
A:
35