#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; j++) {
      if (j == i)
        cout << k;
      else
        cout << "0";
      if (j != n - 1) cout << " ";
    }
    cout << endl;
  }
  return 0;
}
