Problem:
Score : 100 points

Problem Statement

You are given three strings A, B and C. Check whether they form a word chain.

More formally, determine whether both of the following are true:

The last character in A and the initial character in B are the same.

The last character in B and the initial character in C are the same.

If both are true, print YES. Otherwise, print NO.

Constraints

A, B and C are all composed of lowercase English letters (a - z).

1 ≤ |A|, |B|, |C| ≤ 10, where |A|, |B| and |C| are the lengths of A, B and C, respectively.

Input

Input is given from Standard Input in the following format:

A B C

Output

Print YES or NO.

Sample Input 1

rng gorilla apple

Sample Output 1

YES

They form a word chain.

Sample Input 2

yakiniku unagi sushi

Sample Output 2

NO

A and B form a word chain, but B and C do not.

Sample Input 3

a a a

Sample Output 3

YES

Sample Input 4

aaaaaaaaab aaaaaaaaaa aaaaaaaaab

Sample Output 4

NO

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

(let ((a (read))
      (b (read))
      (c (read)))

  (defun get-f (x)
    (car (concatenate 'list (symbol-name x))))

  (defun get-b (y)
    (car (reverse (concatenate 'list (symbol-name y)))))


  (format t "~A~%"
          (if (and (char= (get-b a) (get-f b)) (char= (get-b b) (get-f c)))
            'yes
            'no)))