What is wrong?

```
function uniteUnique(...arr) {
let newArr = [];
let ret = [];
let x;
for (let i = 1; i < arr.length; i++){
x = 0;
newArr = arr[i].filter((a) => {
if ((a !== 1) && (a !== 2) && (a !== 3)){
x++;
return a;
}
})
if (x > 0){
ret.push(newArr);
}
}
ret.unshift(arr[0]);
return ret;
}
uniteUnique([1, 3, 2], [5, 2, 1, 4], [2, 1]);
```
```