Appeal from summary denial of movant-defendant’s Rule 27.26 motion. He challenges the 20-year persistent-offender sentence imposed on his plea of not guilty to second-degree robbery. See 638 S.W.2d 802 (Mo.App. 1982).

Defendant’s only ground here is that his sentence exceeded the ten years received by his accomplice on a guilty plea. That is irrelevant.

We presume the validity of legislatively prescribed punishment. State v. Higgins, 592 S.W.2d 151[2, 3] (Mo. banc 1979) and Parton v. State, 545 S.W.2d 338[14-16] (Mo.App. 1976).

Affirmed.