Start   ADR r0, UPC ;register r0 points to the upc string
        MOV r1, #6 ;Initializing the loop counter to 12
        MOV r2, #0 ;clearing the sum in r2
        MOV r3, #0  ;clearing r3 for the sum
Loop    LDRB r4,[r0]
        SUBS r4,r4,#48
        ADD r2, r2, r4 ;add the odds
        ADD r0,r0, #1 ; point to the next element
        LDRB r4,[r0]
        SUBS r4,r4,#48
        ADD r3,r3, r4 ; add the evens
        SUBS r1,r1,#1
        BNE Loop