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: Accepted)

import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		solve();
	}

	public static void solve() {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		final int MOD = 1000000007;

		//入力
		String a = sc.next();
		String b = sc.next();
		String c = sc.next();
		sc.close();

		//処理
		boolean f = (a.charAt(a.length()-1) == b.charAt(0) && b.charAt(b.length()-1) == c.charAt(0));

		//出力	
		out.println(f ? "YES" : "NO");
		out.flush();
	}

	static class Pair{
		int a,b;
		public Pair(int a, int b){
			this.a = a;
			this.b = b;
		}
	}
}