This clue is encrypted with a LETTER NUMBERS cipher. That means each number equals the number letter it is on the alphabet. A = 1, B = 2, Y = 25, Z = 26. There are dashes between letters and spaces between words.
12-1-19-20 20-15 19-16-9-14 16-1-14-4-15-18-1-19 23-8-5-5-12
GO!