#include <bits/stdc++.h>
using namespace std;
int dx[] = {0, 0, 1, -1, 1, 1, -1, -1};
int dy[] = {1, -1, 0, 0, 1, -1, 1, -1};
int main() {
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < n; ++j) i == j ? cout << m << ' ' : cout << 0 << ' ';
    cout << endl;
  }
  return 0;
}
