instruction:
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.
question:
Marcus has 210 baseball cards . He has 58 more than Carter . How many baseball cards does Carter have ?
answer:
152


question:
Joan has 40 blue balloons Melanie has 41 blue balloons . How many blue balloons do they have in total ?
answer:
81


question:
A waiter at ' The Greasy Spoon ' restaurant had 39 customers to wait on . During the lunch rush he added another 12 customers . If 49 of the customers did n't leave him a tip , how many customers did leave a tip ?
answer:

2