#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n - 1; j++) {
      if (i == j)
        cout << k << ' ';
      else
        cout << "0 ";
    }
    if (i == n - 1)
      cout << k << endl;
    else
      cout << "0" << endl;
  }
  return 0;
}
