PROG SIEVE
N=INDEX 198
I=2
WHIL I LE SIZE N * .5   
DO   
   IF N(I) EQ 0
   THEN EXIT
   ELSE
      J=IxI
      WHILE J LE SIZE N
      DO
         N(J)=0
         J=J+I
      ENDW
   ENDI
   I=I+1
ENDW 
N
ENDP