13. (12 points) The numbers on the dartboard represent the points scored for hitting that area, and a miss is recorded as 0 points. Xiao Ming throws three darts at the dartboard shown in the figure, and then adds up the scores of the three darts. What is the smallest total score that Xiao Ming cannot achieve? $\qquad$
【Answer】Solution: If an odd score is obtained, there are two possibilities: three odd scores, which could be $3,5,7,9,25,27$, $29,47, \cdots$,

one odd score and at most two even scores, 8 and 12 can form $8,12,16,20,24$, so it could be 1,3, $11,13,15,17,19,21,23,25,27,31, \cdots$ cannot form 33.

If an even score is obtained, there are two possibilities: at most three even scores, 8 and 12 can form all multiples of 4 from 8 to 36.

two odd scores and one even score, two odd scores can be $2,4,6,24,26,46$, can form $6+12=$ 18, cannot form 22.

Therefore, the answer is 22.