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 Scala (2.11.7) (judge verdict: Accepted)

import java.util.Scanner;

object Main {

  def main(args: Array[String]): Unit = {
    val scan: Scanner = new Scanner(System.in)

    val wordA = scan.next()
    val wordB = scan.next()
    val wordC: String = scan.next()


    val lastWordWordA = wordA.charAt(wordA.length() - 1)
    val firstWordWordB = wordB.charAt(0)

    val lastWordWordB = wordB.charAt(wordB.length() - 1)
    val firstWordWordC = wordC.charAt(0)

    if (lastWordWordA == firstWordWordB && lastWordWordB == firstWordWordC) {
      println("YES")
    } else {
      println("NO")
    }
  }
}