procedure befriend_ent(s)
   local lseq, i, tail

   s := copy(s)

   lseq := [get(s)] | return []

   while i := get(s) do
      lseq |||:= wander(lseq[-1], i)

   return lseq

end

procedure wander(j, i)	
   local result, k, incr

   result := [j]

   repeat {
      k := i - result[-1]
      if abs(k) = 1 then {
         put(result, i)
         break
         }
      incr := [1, -1]
      if k < 0 then
         every 1 to -k do
            put(incr, -1)
      else
         every put(incr, 1)
      put(result, result[-1] + ?incr)
      if result[-1] == i then break
      }

   if *result > 1 then get(result)

   return result

end