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.

[EX Q]: Fred has 40 baseball cards . Keith bought 22 of Fred 's baseball cards . How many baseball cards does Fred have now ?
[EX A]: 18

[EX Q]: Sean has 55 blocks . 29 are eaten by a hippopotamus . How many blocks will Sean have ?
[EX A]: 26

[EX Q]: Sam has 86 yellow and 20 green marbles . Joan took 25 of Sam 's yellow marbles . How many yellow marbles does Sam now have ?
[EX A]:
61