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++ (GCC 9.2.1) (judge verdict: Accepted)

// lcmとか__builtin_popcountとかはg++ -std=c++17 default.cppみたいなかんじで

#include <bits/stdc++.h>
#define mod 1000000007
#define INF LLONG_MAX
#define ll long long
#define ln cout<<endl
#define Yes cout<<"Yes"<<endl
#define No cout<<"No"<<endl
#define REP(i,m,n) for(ll i=(ll)(m);i<(ll)(n);i++)
#define rep(i,n) REP(i,0,n)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
using namespace std;
ll dx[4]={1,0,-1,0};
ll dy[4]={0,1,0,-1};

int main() {
    cin.tie(0);
   	ios::sync_with_stdio(false);

    ll  a,b,c,d,e,n,maxi=0,f=0,mini=INF,sum=0,q;
	string str,g;
    string stra,strb,strc;
    cin>>stra>>strb>>strc;
    if(stra[stra.length()-1]==strb[0]&&strb[strb.length()-1]==strc[0]) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;

    return 0;
}