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: Wrong Answer)

using System;
class Program
{
	static void Main(string[] args)
	{
        string s = Console.ReadLine();
        string result = "";
        if (s.Length == 6){
            result = equalCheck(s.Substring(2,1),s.Substring(3,1));
            result = equalCheck(s.Substring(4,1),s.Substring(5,1));
        } else {
            result = "No";
        }
        Console.WriteLine(result);
	}

    static string equalCheck(string target1,string target2){
        if (target1 == target2){
            return "Yes";
        } else {
            return "No";
        }
    }
}