#include <bits/stdc++.h>
using namespace std;
int main() {
  int T = 1;
  while (T--) {
    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 << " ";
      }
      cout << endl;
    }
  }
}
