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)

a = str(input())
k = "keyence"
lk = len(k)

ok = 0

if len(a) >= lk:
    s1 = a.find(k)
    s2 = len(a[s1:])
    if s1 == 0 or s2 == lk:
        ok = 1

    for i in range(lk):
        s1 = a.find(k[:i])
        s2 = a[s1+i:].find(k[i:])
        if s1 >= 0 and s2 >= 0:
            if s1 == 0 and len(a[s1+i+s2:]) == len(k[i:]):
                ok = 1

if ok == 1:
  print("YES")
else:
  print("NO")