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: Accepted)

#include <stdio.h>
int main(){

  int i,last;
  char a[3][11];

  for(i = 0; i < 3; i++) scanf("%s",a[i]);

  for(i = 0; i < 11; i++){
    if(a[0][i] == '\0'){
      last=i-1;
      break;
    }
  }

  if(a[0][last] != a[1][0]){
    printf("NO\n");
    return 0;
  }

  for(i = 0; i < 11; i++){
    if(a[1][i] == '\0'){
      last=i-1;
      break;
    }
  }

  if(a[1][last] != a[2][0]){
    printf("NO\n");
    return 0;
  }

  printf("YES\n");
  return 0;

}