60     a

    60     a

    61     b

    61     b

    62 

    62 

    63 We define the two values

    63 We define the two values

    64 ::

    64 ::

    65     temp = a

    66     temp = a

    66     a = b

    67     a = b

    67     b = temp

    68     b = temp

    68 

    69 

    69     a

    70     a