You are given a math word problem and you are supposed to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Jason has 3 Pokemon cards . Benny bought 2 of Jason 's Pokemon cards . How many Pokemon cards does Jason have now ?
1

A pet store had 12 siamese cats and 20 house cats . During a sale they sold 20 cats . How many cats do they have left ?
12

In fourth grade there were 4 students at the start of the year . During the year 3 students left and 42 new students came to school . How many students were in fourth grade at the end ?

43