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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

function Main(input) {
    input = input.split(" ");
    one = false;
    nana = false;
    nine = false;
    four = false;
    for(i = 0; i < 4; i++){
        if(input[i] === "1") one=true;
        if(input[i] == "7") nana = true;
        if(input[i] == "4") four = true;
        if(input[i] == "9") nine = true;
    }
    console.log((one && nana && nine && four) ? "YES" : "NO")
}


Main(require("fs").readFileSync("/dev/stdin", "utf8"));