allocate-registers n, cont, ten, base-case, body, sp, one, write-digs, digit

        li sp, 0

        li ten, 10
        li one, 1
        li body, body-label
        li write-digs, write-digits

        read n
        li cont, after-top-level

write-digits:                   ; writes digits of n (MSD to LSD) where n >= 0, then jumps to cont
        slt base-case, n, ten
        jeqz base-case, body
        write n
        j cont

body-label:
        st n, sp
        add sp, sp, one
        st cont, sp
        add sp, sp, one
        quo n, n, ten
        li cont, print-last-digit
        j write-digs

after-top-level:
        halt

print-last-digit:      
        sub sp, sp, one
        ld cont, sp 
        sub sp, sp, one
        ld n, sp
        rem digit, n, ten
        write digit
        j cont