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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int strlen(char *s)
{
	int i = 0;
	while (s[i]) i++;
	return i;
}

int cheackstr(char *s)
{
	for (int i = 3, cnt = 0; cnt < 2; i += 2, cnt++)
	{
		if (s[i] != s[i])
			return 0;
	}
	return 1;
}

int main(void)
{
	char s[7] = {};
	scanf("%s", s);
	if (strlen(s) != 6) return 0;
	if (cheackstr(s)) puts("Yes");
	else puts("No");
	return 0;
}