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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

public class keyence2019b {
  static public void Main(){
    string s = Console.ReadLine();

    int n = s.Length;

    string keyence = "keyence";
    for (int i = 0; i <= 7; i++) {
      if (s.Substring(0, i) == keyence.Substring(0, i) && s.Substring(n-7+i, 7-i) == keyence.Substring(i, 7-i)) {
        Console.WriteLine("YES");
        return;
      }
    }

    Console.WriteLine("NO");

    return;
  }
}