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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

 public class Hello{
    public static void Main(){
        // Here your code !
        string input;
        input = System.Console.ReadLine();
        string[] abc = input.Split(' ');
        
        string result = Last(abc[0])==First(abc[1]) && Last(abc[1])==First(abc[2]) ? "YES": "NO";

        System.Console.WriteLine(result );
    }
    
    public static string First (string word)
    {
        return word.Substring(0,1);
    }
    
    public static string Last (string word)
    {
        return word.Substring(word.Length-1,1);
    }
}