MAIN	START
	OUT	STR,LEN
    LAD	GR1,STR
    LD	GR2,LEN
    CALL	REV
	OUT	STR,LEN
    RET
STR	DC	'12345'
LEN	DC	5
    END
REV	START
	LAD	GR3,1
RPU	CPA	GR2,GR3
	JMI	RNEXT
    LD	GR4,GR1
    ADDA	GR4,GR3
    LD	GR4,-1,GR4
	PUSH 0,GR4
    LAD	GR3,1,GR3
    JUMP	RPU
RNEXT    LAD	GR3,1
RPO	CPA	GR2,GR3
	JMI	PFIN
    POP	GR4
    LD	GR5,GR1
    ADDA	GR5,GR3
    ST	GR4,-1,GR5
    LAD	GR3,1,GR3
    JUMP	RPO
PFIN	RET
	END