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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Xml;

class Program
{
	static void Main(string[] args)
	{
		string s = Console.ReadLine();
		if (s.Substring(2, 1) == s.Substring(3, 1) && s.Substring(4, 1) == s.Substring(5, 1))
		{
			Console.WriteLine("Yes");
		}
		else
		{
			Console.WriteLine("No");
		}
	}
}


//string s = Console.ReadLine();
//int[] inputintArray = Console.ReadLine().Split(' ').Select(i => int.Parse(i)).ToArray();
//int H = inputintArray[0];
//int W = inputintArray[1];
//int N = int.Parse(Console.ReadLine());
//int[] a = Console.ReadLine().Split(' ').Select(i => int.Parse(i)).ToArray();

//Console.WriteLine(ans);