BEGIN {print "# CustomFizzBuzz:"}

$1 %  2 == 0 {x = x "A"}
$1 %  3 == 0 {x = x "B"}
$1 %  5 == 0 {x = x "C"}

!x    {print $1; next}
      {print " ",x; x=""}
             
END   {print "# Done."}