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: Calculate prob of sequence pd when two letters picked without replacement from {d: 2, c: 1, m: 2, p: 2, z: 1}.

Output: 1/14


Input: Consider Input: Suppose 2*n + 2*n = 4. Suppose -n = f - 2. What is the highest common divisor of f and 5?

Output: 1


Input: Consider Input: Solve 9 + 7 = 4*c for c.


Output: 4