What is the appropriate sentence for a defendant with three or more prior theft convictions?

On July 10, 2013, defendant pleaded no contest to the charge of petty theft with three or more prior theft convictions ( 666, subd. (a)) and admitted the allegations that he had a prior strike conviction ( 667, subds. (b)-(i), 1170.12) and two prison priors ( 667.5, subd. (b)). After denying defendant's motion pursuant to People v. Superior Court (Romero) (1996) 13 Cal.4th 497, 53 Cal.Rptr.2d 789, 917 P.2d 628, the trial court imposed the indicated maximum sentence of four years.