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 (2.13.1) (judge verdict: Accepted)

object Main extends App {
  val inputs: Seq[String] = scala.io.Source.stdin.getLines().toList
  val nums = inputs.head.split(" ")
  val a = nums(0)
  val b = nums(1)
  val c = nums(2)

  println(solve(a, b, c))

  private def solve(a: String, b: String, c: String): String = {
    if (a(a.size - 1) == b(0) && b(b.size - 1) == c(0)) {
      "YES"
    } else {
      "NO"
    }
  }
}