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