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 Python (3.4.3) (judge verdict: Wrong Answer)

# -*- coding: utf-8 -*-

keyStr=input()
keyence="keyence"

before=""
after=""
chkflg=False

if keyStr.find(keyence) >= 0:
  print("YES")

for char in range(len(keyence) -1):
  before=keyence[0:char+1]
  after=keyence[char+1:len(keyence)]
  
  bindex= keyStr.find(before)
  if bindex >= 0:
    if keyStr[bindex+len(before):len(keyStr)].find(after) >= 0:
      print("YES")
      chkflg=True
      break

if chkflg == False:
  print("NO")