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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<iostream>
#include<string.h>
using namespace std;

string ch(int,int,int,int);
int main(void)
{
    int a,b,c,d;
    cin>>a>>b>>c>>d;
    cout<<ch(a,b,c,d)<<endl;
    return 0;
} 

string ch(int a,int b,int c,int d)
{
    if(a!=1||b!=1||c!=1||d!=1) return "NO" ; 
    if(a!=9||b!=9||c!=9||d!=9) return "NO";
    if(a!=7||b!=7||c!=7||d!=7)return "NO";
    if(a!=4||b!=4||c!=4||d!=4) {return "NO";}
    else return "YES";
}