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: Wrong Answer)

#include<stdio.h>
int main()
{
	char a[11],b[11],c[11];
	int i=0,j=0,k=0,y=0,x=0;
	scanf("%s",a);
	getchar();
	scanf("%s",b);
	getchar();
	scanf("%s",c);
	while(a[i]!='\0')
		i++;
	while(b[j]!='\0')
		j++;
	while(c[k]!='\0')
		k++;
    if(a[i-1]==b[0])
		x=1;
	if(b[j-1]==c[0])
		y=1;
	if(i==1&&j==1&&k==1&&x==1&&y==1)
		printf("YES\n");
	else if(x==1&&y==1)
		printf("YES\nThey form a word chain.\n");
	else if(x==1&&y==0)
		printf("NO\nA and B form a word chain, but B and C do not.\n");
	else
		printf("NO\n");
	return 0;
}