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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

main(){
    int a,b,c,d;
    scanf("%d %d %d %d",&a,&b,&c,&d);
    int i,count=0;

    int box[4];
    box[0]=a;
    box[1]=b;
    box[2]=c;
    box[3]=d;
    
    for(i=0;i<4;i++){
        if(box[i]==1){
            count++;
        }else if(box[i]==7){
            count++;
        }else if(box[i]==9){
            count++;
        }else if(box[i]==4){
            count++;
        }
    }

    if(count==4){
        printf("YES\n");
    }else{
        printf("NO\n");
    }

    return 0;
}