set     S0, "00000000000000000000001001000010"
        length  I0, S0
        set     I1, 1
        set     I2, 0
LOOP:   dec     I0
        substr  S1, S0, I0, 1
        if      S1, INC
RETURN: mul     I1, I1, 2
        ge      I0, 0, LOOP
        print   I2
        print   "\n"
        end
INC:    add     I2, I1
        branch  RETURN