```
function largestOfFour(arr) {
// You can do this!
let max = 0;
for(let i = 0; i < arr.length; i++){
for(let j = 0; j < arr[i].length; j++){
if(arr[i][j] > max){
max = arr[i][j];
}
}
}
for(let i = 0; i < arr.length; i++){
if(arr[i].includes(max)){
return arr;
}
}
}
largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);
```

What is the problem with the code ?