输出3-20之间的素数，填空

SET TALK OFF
CLEAR
FOR M=3 TO _____ STEP 2
N=INT(SQRT(M))
FOR I=3 TO N
IF _____(M,I)=0
EXIT
ENDIF
ENDFOR
SET TALK ON
RETURN

老大，怎么显示结果呢？
把“？M”放在哪里？