Teacher:You are given a math word problem and you are supposed to only use subtraction on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
Teacher: Now, understand the problem? Solve this instance: Context: A farmer had 171 tomatoes in his garden. If he picked 134 of them yesterday and 30 today.

Question: How many will he have left after today?
Student:
7