procedure main(arglist)
    local b  # the current buffer (string)
    local l  # the last string
    local L  # a \n delimited accumulation of all the longest strings

    while b := read() do {
        /l := b      # primes l on first pass
        b ? ( move(*l), if move(1) then L := (l := b) || "\n" else if move(0) then L := (\L|"") || b || "\n")
            #       move(*l) - fails if b is not l characters long
            #       move(1)  - succeeds/fails if the string is longer and triggers a reset of L
        }

    write(\L)
end