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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String AnsS = "keyence";
        String s = sc.nextLine();

        boolean isAns = true;

        int i = 0;
        int j = 0;
        int checkCnt = 0;
        while (checkCnt < AnsS.length()) {
            if (s.charAt(i) == AnsS.charAt(i)) {
                i++;
            }
            else if (s.charAt(s.length() - j - 1) == AnsS.charAt(AnsS.length() - j - 1)) {
                j++;
            }
            else {
                isAns = false;
            }
            checkCnt++;
        }

        System.out.println(isAns ? "YES" : "NO");
    }
}