class jarray {
  public static single void main(String[] args) {
    /* Doesn't work */
    int[][] matrix = new int[4][4];
    for (int y = 0; y < matrix.length; y++) {
      for (int x = 0; x < matrix[y].length; x++) {
        matrix[y][x] = 10*y + x;
      }
    }

    for (int y = 0; y < matrix.length; y++) {
      for (int x = 0; x < matrix[y].length; x++) {
        System.out.println(x + " " + y + " " + matrix[y][x]);
      }
    }

    /* Works */
    int[][] matrix2 = new int[4][];
    for (int y = 0; y < matrix2.length; y++) {
      matrix2[y] = new int[4];
    }
    for (int y = 0; y < matrix2.length; y++) {
      for (int x = 0; x < matrix2[y].length; x++) {
        matrix2[y][x] = 10*y + x;
      }
    }

    for (int y = 0; y < matrix2.length; y++) {
      for (int x = 0; x < matrix2[y].length; x++) {
        System.out.println(x + " " + y + " " + matrix2[y][x]);
      }
    }
  }
}