#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  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 << "  ";
      }
    }
    cout << "\n";
  }
}
