Task: Question Understanding
Input (English): Let z be -3 + 6 + 4/2. Suppose -28 = -4*g - 0*u - z*u, 5*u - 24 = -2*g. Suppose -4*i = -3*o + o + g, o = 3*i. What is the highest common factor of o and 3?
Output (English): numbers