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).

Input: Consider Input: Solve 96*r - 13 = 91*r + 2*u, 3*u - 12 = -3*r for r.

Output: 3


Input: Consider Input: Let y(m) = m**2 - m + 1. Let i be y(2). Suppose -9 = 2*n + 3*j, -i*n + 3*j = -4 - 5. Suppose -d + 4 = b, -2 = 4*d - 5*b - n. What is the units digit of d?

Output: 2


Input: Consider Input: In base 15, what is d + -e?


Output: -1