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>
using namespace std;
void ABC60(void);
void ABC61(void);
void ABC62(void);
void ABC63(void);
void ABC64(void);
void ABC65(void);
void ABC66(void);
void ABC67(void);
void ABC68(void);
void ABC69(void);

int main(void){
    ABC60();
}

void ABC60(void){
    string a,b,c;
    int i,j;
    cin >> a >> b >> c;
    for(i=0;a[i]!='\0';++i){}
    for(j=0;b[j]!='\0';++j){}
    if((a[i-1]==b[0])&&(b[j-1]==c[0]))cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
}