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() {
	int n1,n2,n3,n4,w=0,x=0,y=0,z=0;
	scanf("%d %d %d %d",&n1,&n2,&n3,&n4);
	if(n1==1 ||n2==1||n3==1||n4==1 )
	w++;
	if(n1==9 ||n2==9||n3==9||n4==9 )
	x++;

if(n1==7||n2==7||n3==7||n4==7 )
	y++;
if(n1==4 ||n2==4||n3==4||n4==4 )
	z++;
if(x==1 && y==1 && z==1 && w==1)
printf("YES");
else
printf("NO");
	return 0;
}