%!PS

% begin library code

/test {
    /test.count test.count 1 add def
    {
        /test.pass test.pass 1 add def
    } {
        ( ) print
        test.count (....) cvs print
        (-fail) print
    } ifelse
} bind def

/test.start {
    print (:) print
    /test.pass 0 def
    /test.count 0 def
} bind def

/test.end {
    ( ) print
    test.count 0 gt {
        (Passed ) print
        test.pass (...) cvs print
        (/) print
        test.count (...) cvs print
        ( \() print
        test.pass 100 mul test.count idiv (...) cvs print
        (%\)) print
        (\r\n) print
    } if
} bind def

/quicksort { % [ a c b ] -> [ a b c ]
    1 dict begin
    /arr exch def
    0 arr length 1 sub quicksort.main
    arr
    end
} bind def

/quicksort.main { % lo hi -> (null)
    3 dict begin
    /hi exch def
    /lo exch def
    /xit false def
    lo 0 lt {
        /xit true def
    } if
    hi 0 lt {
        /xit true def
    } if
    lo hi ge {
        /xit true def
    } if
    xit not {
        /p quicksort.partition def
        lo p quicksort.main
        p 1 add hi quicksort.main
    } if
    end
} bind def

/quicksort.partition {
    3 dict begin
    /pivot arr hi lo add 2 idiv get def
    /i lo 1 sub def
    /j hi 1 add def
    {
        {
            /i i 1 add def
            arr i get pivot ge {
                exit
            } if
        } loop
        {
            /j j 1 sub def
            arr j get pivot le {
                exit
            } if
        } loop
        i j ge {
            j
            exit
        } if
        i j quicksort.swap
    } loop
    end
} bind def

/quicksort.swap {
    2 dict begin
    /bi exch def
    /ai exch def
    arr ai get
    arr bi get
    arr exch ai exch put
    arr exch bi exch put
    end
} bind def

/apush { % [a b] c -> [a b c]
    exch
    [ exch aload length 2 add -1 roll ]
} bind def

/values { % dict -> array of dict values
    [ exch
      {
          exch pop
      } forall
    ]
} bind def

% end library code

/genprimes {
    /mx exch def
    /primesh mx dict def
    2 1 3 {
        primesh exch true put
    } for
    6 6 mx 1 add {
        dup 1 sub exch 1 add 2 exch {
            dup mx le {
                primesh exch true put
            } {
                pop
            } ifelse
        } for
    } for
    /q [ 3 5 7 ] def
    /qi 0 def
    /p 2 def
    /mr mx sqrt cvi def
    {
        p mr le not {
            exit
        } if
        primesh p known {
            p dup mul p mx {
                primesh exch undef
            } for
        } if
        q length qi sub 2 le {
            /q q q q length 1 sub get 4 add apush def
            /q q q q length 1 sub get 2 add apush def
        } if
        /p q qi get def
        /qi qi 1 add def
    } loop
    [ primesh { pop } forall ] quicksort
} bind def

/primefactor {
    4 dict begin
    /n exch def
    /f 1 dict def
    /m n def
    n sqrt cvi genprimes {
        /p exch def
        {
            m p mod 0 eq {
                f p known {
                    f p f p get 1 add put
                } {
                    f p 1 put
                } ifelse
                /m m p idiv def
            } {
                exit
            } ifelse
        } loop
        m 1 eq {
            exit
        }
    } forall
    m 1 gt {
        f m known {
            f m f m get 1 add put
        } {
            f m 1 put
        } ifelse
    } if
    f
    end
} bind def

/moebius {
    1 dict begin
    /z 0 def
    primefactor values {
        1 gt {
            /z 0 def
            exit
        } if
        /z z 1 add def
    } forall
    z 0 eq {
        0
    } {
        z 2 mod 0 eq {
            1
        } {
            -1
        } ifelse
    } ifelse
    end
} bind def

(moebius) test.start
5 moebius -1 eq test
10 moebius 1 eq test
20 moebius 0 eq test
test.end