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: Wrong Answer)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var S = Console.ReadLine();
            for(var i =0; i<S.Length; i++)
            {
                for(var j=0; j<S.Length-i; j++)
                {
                    var sub1 = S.Substring(i, j);
                    for(var k=0; k<S.Length-i-j; k++)
                    {
                        var sub2 = S.Substring(i+j+k, S.Length - i - j - k);
                        if(sub1+sub2=="keyence")
                        {
                            Console.WriteLine("YES");
                            return;
                        }
                    }
                }
            }
            Console.WriteLine("NO");
        }

    }
}
//A