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: Accepted)

#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()

using namespace std;
using ll = long long;

int main(void)
{
    int str;
    int one = 0;
    int seven = 0;
    int nine = 0;
    int four = 0;
    rep(i, 4)
    {
        cin >> str;
        if (str == 1)
        {
            one = 1;
        }
        else if (str == 9)
        {
            nine = 1;
        }
        else if (str == 7)
        {
            seven = 1;
        }
        else if (str == 4)
        {
            four = 1;
        }
    }
    if (one == 1 && seven == 1 && nine == 1 && four == 1)
    {
        cout << "YES" << endl;
    }
    else if (one == 1 || seven == 1 || nine == 1 || four == 1)
    {
        cout << "NO" << endl;
    }
    return 0;
}