class Main {
public static void main(String[] args) {
int[][] data = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}};
boolean[][] flag = new boolean[3][4];
// for (int i = 0; i < flag.length ; i++) {
// for (int j = 0; j < flag[0].length ; j++) {
// System.out.println(flag[i][j]);
// }
// }
int N = 5;
int [] points = new int [N];
int i = 0;
while (i < N) {
int rowIndex = (int) (Math.random() * data.length);
int colIndex = (int) (Math.random() * data[0].length);
if (flag[rowIndex][colIndex] == false) {
points[i] = data[rowIndex][colIndex];
System.out.println(points[i]);
flag[rowIndex][colIndex] = true;
i = i + 1;
}
}
}
}
