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: Wrong Answer)

import java.io.*;

class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        String str = br.readLine();

        String[] data = str.split("");

        String[] keyence = { "k", "e", "y", "e", "n", "c", "e" };

        int x = 0;
        int y = 0;
        int z = 0;
        for (int i = 0; i < keyence.length; i++) {
            if (data[x].equals(keyence[i])) {
                x++;
            } else {
                if (y == 0) {
                    x = x + (data.length - keyence.length) - 1;
                    y = 1;
                } else {
                    z = 1;
                    break;
                }
            }
        }

        if (z == 1)
            System.out.println("NO");
        else
            System.out.println("YES");
    }
}