(
  ( hailstone
  =   L len
    .   !arg:?L
      &   whl
        ' ( !arg:~1
          & (!arg*1/2:~/|3*!arg+1):?arg
          & !arg !L:?L
          )
      & (!L:? [?len&!len.!L)
  )
& ( reverse
  =   L e
    .   :?L
      & whl'(!arg:%?e ?arg&!e !L:?L)
      & !L
  )
& hailstone$27:(?len.?list)
& reverse$!list:?first4 [4 ? [-5 ?last4
& put$"Hailstone sequence starting with "
& put$!first4
& put$(str$(" has " !len " elements and ends with "))
& put$(!last4 \n)
& 1:?N
& 0:?max:?Nmax
&   whl
  ' ( !N+1:<100000:?N
    &   hailstone$!N
      : (   >!max:?max&!N:?Nmax
          | ?
        . ?
        )
    )
&   out
  $ ( str
    $ ( "The number <100000 with the longest hailstone sequence is "
        !Nmax
        " with "
        !max
        " elements."
      )
    )
);