(defparameter ans 0)
(defparameter temp 0)
(loop for char = (read-char nil nil) do
    (if (eq char nil) (return))
    (if (not (eq char #\Newline)) 
        (if (eq char #\x ) (progn
            (setq ans (max ans temp))
            (setq temp 0)
        )   
            (setq temp (+ temp 1)) 
        )   
    )   
)
(setq ans (max ans temp))
(format t "~d~%" ans)