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: Accepted)

#include <stdio.h>
int main(void){
  int s[3],i;
  for(i=0;i<=3;i++){
    scanf("%d",&s[i]);
  }
  if(s[0]==1||s[1]==1||s[2]==1||s[3]==1){
    if(s[0]==9||s[1]==9||s[2]==9||s[3]==9){
      if(s[0]==7||s[1]==7||s[2]==7||s[3]==7){
        if(s[0]==4||s[1]==4||s[2]==4||s[3]==4){
          printf("YES");
        }
        else printf("NO");
      }
      else printf("NO");
    }
    else printf("NO");
  }
  else printf("NO");
  return 0;
}