import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int k = in.nextInt();
        int[][] matrix = new int[n][n];
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                if (j == i) matrix[i][j] = k;
                else matrix[i][j] = 0;
            }
        }
        for (int[] arr : matrix) {
            for (int a : arr) {
                System.out.print(a + " ");
            }
            System.out.println();
        }
    }
}