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 5.4.1) (judge verdict: Time Limit Exceeded)

#include<stdio.h>

int len(int *s){
  int len;
  
  while(s){
    len++;
  }
  
  return len;
}
 
int main(){
  char a[11], b[11], c[11];
  int alen, blen, clen;
  scanf("%s %s %s", a, b, c);
  
  alen = len(a);
  blen = len(b);
  clen = len(c);
  
  if(a[alen - 1] == b[0] && b[blen - 1] == c[0]){
    printf("YES\n");
  } else {
    printf("NO\n");
  }
  
  return 0;
}