public class Main {
  public static void main(String[] args) {
    // A 2-row, 3-column grid of numbers
    int[][] grid = {
      {1, 2, 3},
      {4, 5, 6}
    };

    // Read the value in row 1, column 2
    System.out.println(grid[1][2]); // 6

    // Change the value in row 0, column 0
    grid[0][0] = 99;
    System.out.println(grid[0][0]); // 99
  }
}