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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
#include<string>
using namespace std;

int main(void){
  string a,b,c;
  cin >> a >> b >> c;
  string A[2];
  string B[2];
  string C[2];
  A[0] = a.front();
  A[1] = a.back();
  B[0] = b.front();
  B[1] = b.back();
  C[0] = c.front();
  C[1] = c.back();
  if(A[1] == B[0] && B[1] == C[0]){
    cout << "YES" << "\n";
  }
  else{
    cout << "NO" << "\n";
  }
}