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.

[Q]: 13 ducks are swimming in a lake . 20 more ducks come to join them . How many ducks are swimming in the lake ?
[A]: 33


[Q]: Harry Hound had a terrible earache yesterday . When I peered into his ears yesterday , I found 36 frisky fleas having a party in his right ear and 85 baby fleas sleeping peacefully in his left ear . I cleaned out Harry Hound 's ears . How many fleas perished ?
[A]: 121


[Q]: Megan 's class is going on a field trip to the zoo . If each van can hold 5 people and there are 25 students and 5 adults going , how many vans will they need ?
[A]:
6