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: Accepted)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.InputMismatchException;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Main {
	
	 static Scanner in = new Scanner(System.in);
	 
   
	public static void main(String args[])throws IOException  {
    while(in.hasNext())
    {
    	
  
    	int []a=new int[4+1];
    	int []vis=new int[11];
    	for(int i=1;i<=4;i++)
    	{
          a[i]=in.nextInt();
          vis[a[i]]++;
    	}
    	if(vis[1]==1&&vis[7]==1&&vis[9]==1&&vis[4]==1)
     	System.out.println("YES");
    	else
    		System.out.println("NO");	
     	
    }

	}
	
 
	
}