INP
        STA NUM

LOOP    LDA FIRST
        SUB NUM
        BRP ENDLOOP
        LDA FIRST
        OUT
        LDA SECOND
        ADD FIRST
        STA ACC
        LDA SECOND
        STA FIRST
        LDA ACC
        STA SECOND
        BRA LOOP

ENDLOOP HLT

FIRST   DAT 0
SECOND  DAT 1
NUM     DAT
ACC     DAT