function multiplyAll(arr) {
  var product = 1;
  // Only change code below this line

  debugger;
  for (var i = 0; i < arr.length; i ++) {
    for (var j = 0; j < arr[i].length; j ++) {
      product *= ([i][j]);
    }
  }


  // Only change code above this line
  return product;
}