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 <algorithm>
#include <cmath>
#include <limits>
#include <vector>
#include <cstdio>
#include <bits/stdc++.h>
#include <set>
#include <map>
#include <stdio.h>
#include <string.h>
#include <stack>
#include <queue>
#include <deque>
#include <numeric>
#include<bits/stdc++.h>
#include <utility>

#define ALL(obj) (obj).begin(), (obj).end()
#define FOR(i,a,b) for(int i = (a); i < (b); i++)
#define RFOR(i,a,b) for(int i = (a); (b) <= i; i--)
#define REP(i,n) for(int i = 0; i < (n); i++)
#define RREP(i,n) for(int i = n; n <= i; i--)
#define ABS(a) ((a < 0) ? ((-1)*(a)) : (a))
#define elif else if
#define MOD 1000000007
#define INF (1<<29)

using namespace std;
using ll = long long;
map <int ,int> mpa,mpb;
typedef pair<ll, ll> P;
priority_queue<P, vector<P>, greater<P>> pque;

int main(){
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  string A, B ,C;
  cin >> A >> B >> C;
  if(A[A.size()-1]==B[0]&& B[B.size()-1]==C[0]){
    cout << "YES" << endl;
  }else{
    cout << "NO" << endl;
  }
  return 0;
}