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: Accepted)

process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', (line) => {
  lines.push(line);
});
reader.on('close', () => {
var array = lines[0];
var n1 = array.indexOf(1);
if (n1 !== -1) {
var n2 = array .indexOf(9);
 if (n2 !== -1){
 var n3 = array .indexOf(7);
  if (n3 !== -1){
 var n4 = array .indexOf(4);
 if (n4 !== -1){
console.log("YES");
} else {
console.log("NO");
}
} else {
console.log("NO");
}

} else {
console.log("NO");
}

} else {
console.log("NO");
}

});