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: Runtime Error)

<?php
if(!iset($argv[1]) || is_array($argv[1]) ) return;

$result = true;
//1文字目と2文字目が相違
if(!isset($argv[1][0]) || !isset($argv[1][1])
   || !($argv[1][0] != $argv[1][1])) $result = false;

//2文字目と3文字目が相違
if(!isset($argv[1][1]) || !isset($argv[1][2])
   || !($argv[1][1] != $argv[1][2])) $result = false;

//3文字目と4文字目が同じ
if(!$result || !isset($argv[1][2]) || !isset($argv[1][3])
  || !($argv[1][2] == $argv[1][3])) $result = false;

//4文字目と5文字目が相違
if(!isset($argv[1][3]) || !isset($argv[1][4])
   || !($argv[1][3] != $argv[1][4])) $result = false;

//5文字目と6文字目が同じ
if(!$result || !isset($argv[1][4]) || !isset($argv[1][5])
  || !($argv[1][4] == $argv[1][5])) $result = false;

if($result){
  echo "Yes";
}else{
  echo "No";
}