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 Ruby (2.3.3) (judge verdict: Runtime Error)

use std::io;

fn read_line()-> String {
    let mut s = String::new();
    let _ = io::stdin().read_line(&mut s).unwrap();
    s
}

fn main() {
	let n = read_line().split_whitespace().map(|e|e.parse().unwrap())
	.collect::<Vec<String>>();

	let a = n[0].trim().split("").collect::<Vec<&str>>();
	let b = n[1].trim().split("").collect::<Vec<&str>>();
	let c = n[2].trim().split("").collect::<Vec<&str>>();

	if a[a.len() - 2] == b[1] && b[b.len() - 2] == c[1] {
		println!("YES");
	}else{
		println!("NO");
	}

}