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(); } } }