Problem:
Score : 200 points

Problem Statement

A string is called a KEYENCE string when it can be changed to keyence by removing its contiguous substring (possibly empty) only once.

Given a string S consisting of lowercase English letters, determine if S is a KEYENCE string.

Constraints

The length of S is between 7 and 100 (inclusive).

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If S is a KEYENCE string, print YES; otherwise, print NO.

Sample Input 1

keyofscience

Sample Output 1

YES

keyence is an abbreviation of key of science.

Sample Input 2

mpyszsbznf

Sample Output 2

NO

Sample Input 3

ashlfyha

Sample Output 3

NO

Sample Input 4

keyence

Sample Output 4

YES

Solution in PHP7 (7.0.15) (judge verdict: Accepted)

<?php
$s=trim(fgets(STDIN));
$n=strlen($s);
$ans='keyence';

$i=0;
while($i<7){
	if($s[$i]===$ans[$i]){
		++$i;
	}else{
		break;
	}
}

$j=0;
while($j<7){
	if($s[$n-1-$j]===$ans[6-$j]){
		++$j;
	}else{
		break;
	}
}

echo ($i+$j>=7)?'YES':'NO';