A health study asks participants, “Do you exercise in the morning or evening?” Responses are 'morning', 'evening', and 'never'. Use a sign test to test if the proportion exercising in the morning equals the proportion exercising in the evening. Assign $+$ to 'morning', $-$ to 'evening', and $0$ to 'never'. Suppose there are $12$ 'morning', $17$ 'evening', and $6$ 'never' responses. Use $\alpha =0.05$. What is the $p$-value?