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: Runtime Error)

S = list(input())
L = list('keyence')
if len(L) > len(S):
	print('NO')
else:
    while L[0] == S[0]:
        L = L[1:]
        S = S[1:]
    while len(L) != 0 and L[-1] == S[-1]:
        L = L[:-1]
        S = S[:-1]
    if L == []:
        print('YES')
    else:
        print('NO')