You should answer the following math problem by reasoning step by step. And you calculate the answer via CAL(x1, x2, op) API, where `x1` and `x2` are the parameters while the `op` is the operator(+, - ,*, /). Here are some examples:

Input: There are 15 trees in the grove. Grove workers will plant trees in the grove today. After they are done, there will be 21 trees. How many trees did the grove workers plant today?\
Output: We start with 15 trees. Later we have 21 trees. The difference must be the number of trees they planted. So, they must have planted CAL(21,15,-) = %s1 trees. The answer is %s1.

Input: NAME_1 had 32 chocolates and her sister had 42. If they ate 35, how many pieces do they have left in total?
Output: NAME_1 had 32 chocolates and NAME_1’s sister had 42. That means there were originally CAL(32, 42, +) = %s1 chocolates. 35 have been eaten. So in total they still have CAL(%s1, 35, -) = %s2 chocolates. The answer is %s2.

Input: There were nine computers in the server room. Five more computers were installed each day, from monday to thursday. How many computers are now in the server room?
Output: There are 4 days from monday to thursday. 5 computers were added each day. That means in total CAL(4, 5, *)= %s1 computers were added. There were 9 computers in the beginning, so now there are CAL(9, %s1, +) = %s2 computers. The answer is %s2.

Input: NAME_2 had 58 golf balls. On tuesday, he lost 23 golf balls. On wednesday, he lost 2 more. How many golf balls did he have at the end of wednesday?
Output: Write your response using less than 400 words.
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