Problem:
Score : 100 points

Problem Statement

You are given four digits N_1, N_2, N_3 and N_4. Determine if these can be arranged into the sequence of digits "1974".

Constraints

0 \leq N_1, N_2, N_3, N_4 \leq 9

N_1, N_2, N_3 and N_4 are integers.

Input

Input is given from Standard Input in the following format:

N_1 N_2 N_3 N_4

Output

If N_1, N_2, N_3 and N_4 can be arranged into the sequence of digits "1974", print YES; if they cannot, print NO.

Sample Input 1

1 7 9 4

Sample Output 1

YES

We can get 1974 by swapping N_2 and N_3.

Sample Input 2

1 9 7 4

Sample Output 2

YES

We already have 1974 before doing anything.

Sample Input 3

1 2 9 1

Sample Output 3

NO

Sample Input 4

4 9 0 8

Sample Output 4

NO

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.Scanner;
public class Main{
	public static void main(String[]args){
	Scanner scan=new Scanner(System.in);
	String a=scan.next();
	boolean bool=false;
	for(int i=0;i<a.length();i++) {
		for(int j=0;j<a.length()-i+1;j++) {
			String str1=a.substring(0,j);
			String str2=a.substring(j+i,a.length());
			String str=str1+str2;
			if(str.equals("keyence")) {
				bool=true;
			}
		}
	}
	System.out.println(bool?"YES":"NO");
	}
}