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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
import java.lang.*;

class Main {

    public static void main(String[] a) {

        Scanner sc = new Scanner(System.in);

        String strA = sc.next();
        String strB = sc.next();
        String strC = sc.next();


        // 判定
        boolean isShiritori = (strA.substring( strA.length() )).equals(strB.substring(0,1)) && 
                              (strB.substring( strB.length() )).equals(strC.substring(0,1));

        if (isShiritori) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
}