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<string.h>
 
int main(){
    int ans = 0, l = 0, i;
    char s[101], k[] = "keyence";
    char *ret;
    scanf("%s", s);
    l = strlen(s);
    if(l < 7){
        puts("NO");
        return 0;
    }

    for(i = 0; i < 7; ++i){
        if(s[i] != k[i]) break;
        if(i == 6) ans = 1;
    }

    for(i = l - 7; i < l; ++i){
        if(s[i] != k[i - l + 7]) break;
        if(i == l - 1) ans = 1;
    }

    for(i = 0; i < strlen(s); ++i){
        if(s[i] == k[i]) {
            l = i;
        }else break;
    }
    if((ret = strstr(&s[strlen(s) - l - 2], &k[i])) != NULL) ans = 1;
    if(ans) puts("YES");
    else puts("NO");
    return 0;
}