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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    char s[101],keyence[] = "keyence";
    int i,j,k;
    char *res;
    scanf("%s",s);

    int len = strlen(s);
    for (i = 0; i < len; i++)
    {
        k = 0;
        for (j = 0; j < i; j++)
        {
            if(s[j] == keyence[k])k++;
        }
        if(k != i)
        {
            continue;
        }
        for (j = len - 7 + i; j < len; j++)
        {
            if(s[j] == keyence[k])k++;
        }
        if(k == 7)break;
    }
    printf("%s\n",i == len ? "NO" : "YES");
}