Problem:
Score : 200 points

Problem Statement

Tak performed the following action N times: rolling two dice.
The result of the i-th roll is D_{i,1} and D_{i,2}.

Check if doublets occurred at least three times in a row.
Specifically, check if there exists at lease one i such that D_{i,1}=D_{i,2}, D_{i+1,1}=D_{i+1,2} and D_{i+2,1}=D_{i+2,2} hold.

Constraints

3 \leq N \leq 100

1\leq D_{i,j} \leq 6

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
D_{1,1} D_{1,2}
\vdots
D_{N,1} D_{N,2}

Output

Print Yes if doublets occurred at least three times in a row. Print No otherwise.

Sample Input 1

5
1 2
6 6
4 4
3 3
3 2

Sample Output 1

Yes

From the second roll to the fourth roll, three doublets occurred in a row.

Sample Input 2

5
1 1
2 2
3 4
5 5
6 6

Sample Output 2

No

Sample Input 3

6
1 1
2 2
3 3
4 4
5 5
6 6

Sample Output 3

Yes

Solution in Common Lisp (SBCL 2.0.3) (judge verdict: Accepted)

(in-package :cl-user)
(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (set-dispatch-macro-character #\# #\> #'cl-debug-print:debug-print-reader)

(macrolet ((def-int (b)
             `(progn (deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))
                     (deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))))
           (defs (&rest bits) `(progn ,@(mapcar (lambda (b) `(def-int ,b)) bits))))
  (defs 2 4 7 8 15 16 31 32 62 63 64))

(defconstant +mod+ 1000000007)

(defmacro dbg (&rest forms)
  #+swank (if (= (length forms) 1)
              `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
              `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

;; BEGIN_INSERTED_CONTENTS
(defpackage :cp/run-length
  (:use :cl)
  (:export #:map-run-length))
(in-package :cp/run-length)

(declaim (inline map-run-length))
(defun map-run-length (function seq &key (test #'eql))
  "Applies FUNCTION to each equal successive element of SEQ. FUNCTION must take
two arguments: the first one receives an element in SEQ and the second one
receives the number of the successive elements equal to the first one.

Example: (map-run-length (lambda (x c) (format t \"~D ~D~%\" x c)) #(1 1 1 2 2 1 3))
1 3
2 2
1 1
3 1
"
  (declare (sequence seq)
           (function test function))
  (etypecase seq
    (vector
     (unless (zerop (length seq))
       (let ((prev (aref seq 0))
             (start 0))
         (loop for pos from 1 below (length seq)
               unless (funcall test prev (aref seq pos))
               do (funcall function prev (- pos start))
                  (setf prev (aref seq pos)
                        start pos)
               finally (funcall function prev (- pos start))))))
    (list
     (when seq
       (labels ((recur (lst prev count)
                  (declare ((integer 0 #.most-positive-fixnum) count))
                  (cond ((null lst)
                         (funcall function prev count))
                        ((funcall test prev (car lst))
                         (recur (cdr lst) prev (+ 1 count)))
                        (t (funcall function prev count)
                           (recur (cdr lst) (car lst) 1)))))
         (recur (cdr seq) (car seq) 1))))))

;; BEGIN_USE_PACKAGE
(eval-when (:compile-toplevel :load-toplevel :execute)
  (use-package :cp/run-length :cl-user))
(in-package :cl-user)

;;;
;;; Body
;;;

(defun main ()
  (let* ((n (read))
         (ds (loop repeat n
                   for d1 = (read)
                   for d2 = (read)
                   collect (= d1 d2))))
    (map-run-length (lambda (bool count)
                      (when (and bool (>= count 3))
                        (write-line "Yes")
                        (return-from main)))
                    ds)
    (write-line "No
")))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    #+os-windows (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)
    #+os-unix (run-program "xsel" '("-b" "-o") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let* ((*standard-output* (or out (make-string-output-stream)))
         (res (etypecase thing
                (null
                 (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
                   (main)))
                (string
                 (with-input-from-string (*standard-input* (delete #\Return thing))
                   (main)))
                (symbol (5am:run! thing))
                (pathname
                 (with-open-file (*standard-input* thing)
                   (main))))))
    (if out res (get-output-stream-string *standard-output*))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

#-swank
(eval-when (:compile-toplevel)
  (when (and (boundp 'sb-c::*compiler-warning-count*)
             (> sb-c::*compiler-warning-count* 0))
    (sb-ext:quit :unix-status 1)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (5am:is
   (equal "Yes
"
          (run "5
1 2
6 6
4 4
3 3
3 2
" nil)))
  (5am:is
   (equal "No
"
          (run "5
1 1
2 2
3 4
5 5
6 6
" nil)))
  (5am:is
   (equal "Yes
"
          (run "6
1 1
2 2
3 3
4 4
5 5
6 6
" nil))))