#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) {
      cout << (i == j ? k : 0) << ' ';
    }
    cout << endl;
  }
  return 0;
}
