Given a simple high-school level math question, you are required to solve it and provide the final answer. The final answer is always a single number. These questions can range from a variety of topics like simple arithmetic, solving equations, converting a quantity from one unit to another, finding remainders/GCD/LCM, finding probabilities etc. Each question has only one correct answer. This answer can be a positive or negative integer, a fraction or a decimal number. If the answer is a negative number use the hyphen (e.g. -42) symbol for the minus sign. For decimal numbers, do not add extra zeros after the decimal point. For fractional numbers, separate the numerator and denominator using a forward slash (e.g. 3/25).

Ex Input:
Two letters picked without replacement from {x: 8, p: 5, a: 7}. Give prob of sequence xa.

Ex Output:
14/95


Ex Input:
Three letters picked without replacement from {q: 5, b: 3, o: 1}. What is prob of picking 1 o and 2 b?

Ex Output:
1/28


Ex Input:
Calculate -1 - (4 - -2) - -3.

Ex Output:

-4