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 Ruby (2.3.3) (judge verdict: Accepted)

class Array
  # being_deleted must be sorted
  def delete_ats(being_deleted)
    tmp = []
    current = 0
    self.each_with_index do |a, i|
      if being_deleted[current] == i
        current += 1
      else
        tmp << a
      end
    end
    self.replace(tmp)
  end
end

s = gets.chomp.chars
(0..s.size).each do |from|
  (0..s.size - from).each do |length|
    copy = Marshal.load(Marshal.dump(s))
    copy.delete_ats((from...from + length).to_a)
    if copy.join == "keyence"
      puts "YES"
      exit
    end
  end
end
puts "NO"