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)

k = "keyence"
s = input()
j = 0
state = 0
flag = True
for i in range(len(s)):
    if state == 0:
        if s[i] != k[j]:
            state = 1
        else:
            j += 1
    elif state == 1:
        if s[i] == k[j]:
            state = 2
            j += 1
    elif state == 2:
        if s[i] != k[j]:
            flag = False
            break
        else:
            j += 1
    if j == len(k):
        if i == len(s)-1:
            break
        elif state == 0:
            break
        else:
            flag = False
            break
if j != len(k):
    flag = False
if flag:
    print("YES")
else:
    print("NO")