What will be the output of the following Java code?

class multidimention_array 
{
    public static void main(String args[])
    {
        int arr[][] = new int[3][];
        arr[0] = new int[1];
        arr[1] = new int[2];
        arr[2] = new int[3];               
  int sum = 0;
  for (int i = 0; i < 3; ++i) 
      for (int j = 0; j < i + 1; ++j)
                arr[i][j] = j + 1;
  for (int i = 0; i < 3; ++i) 
      for (int j = 0; j < i + 1; ++j)
                sum + = arr[i][j];
  System.out.print(sum); 	
    } 
}