DEF DIGITAL_ROOT N OUT DR,AP
AP=0
DR=N
WHILE DR>9
INC AP
STRDR$=STR$(DR)
NEWDR=0
FOR I=0 TO LEN(STRDR$)-1
INC NEWDR,VAL(MID$(STRDR$,I,1))
NEXT
DR=NEWDR
WEND
END