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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using static System.Math;
public static class P
{
    public static void Main()
    {
        var s = Console.ReadLine();

        Console.WriteLine(
            Regex.IsMatch(s, "^.*keyence$") ||
            Regex.IsMatch(s, "^k.*eyence$") ||
            Regex.IsMatch(s, "^ke.*yence$") ||
            Regex.IsMatch(s, "^key.*ence$") ||
            Regex.IsMatch(s, "^keye.*nce$") ||
            Regex.IsMatch(s, "^keyen.*ce$") ||
            Regex.IsMatch(s, "^keyenc.*e$") ||
            Regex.IsMatch(s, "^keyence.*$") ? "YES" : "NO");
    }
}