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: Wrong Answer)

#include <iostream>
#include <cctype>
#include <cstdlib>
#include <string>
#include <algorithm>
#define rep(i, n) for(int i = 0; i < n; ++i)
using namespace std;

int comp(const void* a, const void* b){
	return *(int*)a - *(int*)b;
}

int main() {
	string a, b, c;
	cin >> a >> b >> c;
	if(a.end() == b.begin() && b.end() == c.begin()){
		cout << "YES" << endl;
	}else{
		cout <<"NO" << endl;
	}
}