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: Accepted)

S = input()
if len(S) == 7:
  print(['NO','YES']["keyence"==S])
  exit()
i = 0
while i < 7 and S[i] == "keyence"[i]:
  i += 1
  
j = -1
while j >= -7 and S[j] == "keyence"[j]:
  j -= 1
  
j *= -1
j -= 1
print(['NO','YES'][i+j>=7])