(letrec* ((n (string->number (read-line)))
          (v (make-vector 10 0))
          (get-data (lambda (n a)
                            (if (zero? n) (reverse a)
                                          (get-data (- n 1)
                                                    (cons (string-split (read-line) " ") a)))))
          (a (get-data n '()))
          (check (lambda (a)
                         (unless (null? a)
                                 (let1 r (map string->number (reverse (cdr (reverse (car a)))))
                                    (begin
                                      (if (equal? (car (reverse (car a))) "NO")
                                          (for-each (lambda (x) 
                                                            (vector-set! v x -1))
                                                    r)
                                          (for-each (lambda (x) 
                                                            (vector-set! v x
                                                              (+ (vector-ref v x) 1)))
                                                    r))
                                      (check (cdr a)))))))
          (get-result (lambda (n mv mi)
                              (let* ((v (vector-ref v n))
                                     (b  (< mv v)))
                                    (if (eq? n 9) (if b n mi)
                                                  (get-result (+ n 1) (if b v mv) (if b n mi)))))))
         (check a)
         (print (get-result 0 (vector-ref v 0) 0)))