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).

Example Input: Suppose a - 6*a + 3*j + 321 = 0, -342 = -5*a - 4*j. What is the greatest common divisor of 165 and a?
Example Output: 33

Example Input: Let a(g) = g**3 - 2*g**2 + g - 2. Let v be a(3). Let x = v + 15. What is the units digit of x?
Example Output: 5

Example Input: In base 10, what is -5 - -4?
Example Output:
-1