1
var thousandSeparator = function (n) {
2
  let ans = "";
3

4
  if (n >= 1000) {
5
    const arr = String(n).split("");
6
    for (let i = 0; i < arr.length; i++) {
7
      let temp = arr.length - i;
8
      if (
9
        (temp === 3 && arr.length > temp) ||
10
        (temp === 6 && arr.length > temp) ||
11
        (temp === 9 && arr.length > temp) ||
12
        (temp === 12 && arr.length > temp)
13
      ) {
14
        ans += ".";
15
      }
16
      ans += arr[i];
17
    }
18
  } else {
19
    ans += n;
20
  }
21

22
  return ans;
23
};