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: Wrong Answer)

#include <stdio.h>
int main(void){

	char s[100];
	char k[8] = "keyence";
	int i, ptr = 0;

	scanf("%s",s);

	for(i=0;i<strlen(s);i++){
		
		if(s[i] == k[ptr]){
			ptr++;
		}
		if(ptr >= 7){
			break;
		}
	}

	if(ptr >= 7){
		printf("YES");
	}else{
		printf("NO");
	}

	return 0;

}