Problem:
Score : 100 points

Problem Statement

A string of length 6 consisting of lowercase English letters is said to be coffee-like if and only if its 3-rd and 4-th characters are equal and its 5-th and 6-th characters are also equal.

Given a string S, determine whether it is coffee-like.

Constraints

S is a string of length 6 consisting of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If S is coffee-like, print Yes; otherwise, print No.

Sample Input 1

sippuu

Sample Output 1

Yes

In sippuu, the 3-rd and 4-th characters are equal, and the 5-th and 6-th characters are also equal.

Sample Input 2

iphone

Sample Output 2

No

Sample Input 3

coffee

Sample Output 3

Yes

Solution in PHP (5.6.30) (judge verdict: Wrong Answer)

<?php

$S = intval(trim(fgets(STDIN)));

$alpha_1 = substr($S, 2, 1);
$alpha_2 = substr($S, 3, 1);
$alpha_3 = substr($S, 4, 1);
$alpha_4 = substr($S, 5, 1);

if($alpha_1 === $alpha_2 and $alpha_3 === $alpha_4){
	echo "Yes";
}else{
	echo "No";
}

?>