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