%%HP: T(3)A(D)F(.);
\<< 0. \-> Icr P M C \GD
  \<< \<-h SQ .18 * 'C'
STO/ 0.
    DO '\GD' STO M P \GD
* 12. / + DUP
      IF \<-Mcr >
      THEN \<-Mcr - Icr
/ \<-Mcr \<-Ig / +
      ELSE \<-Ig /
      END C * 3. RND
DUP
    UNTIL \GD ==
    END M OVER P *
12. / +
  \>>
\>>