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: Runtime Error)

#include <stdio.h>
int main(){
  int a[5];
  for(int i=0;i<5;i++)scanf("%d",a[i]);
  for(int i=0;i<5;i++){
    if(a[i]==1)for(int j=0;j<5;j++){
      if(a[j]==9)for(int k=0;k<5;k++){
        if(a[k]==7)for(int l=0;l<5;l++){
          if(a[l]==4){
            puts("YES");
            return 0;
          }
        }
      }
    }
  }
  puts("NO");
  return 0;
}