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 PHP7 (7.0.15) (judge verdict: Accepted)

<?php
fscanf(STDIN, "%s %s %s", $a, $b, $c);
// $a = 'abc';
// $b = 'cdf';
// $c = 'fgh';
$arrayFirst = str_split($a);
$arraySecond = str_split($b);
$arrayThird = str_split($c);
if($arrayFirst[count($arrayFirst) - 1] === $arraySecond[0]){
  if($arraySecond[count($arraySecond) -1] === $arrayThird[0]){
    echo 'YES';
  }else{
    echo 'NO';
  }
}else{
  echo 'NO';
}
?>