#include <bits/stdc++.h>
using namespace std;
long long int mod = 1e9 + 7;
long long int dx[] = {0, 0, 1, -1};
long long int dy[] = {1, -1, 0, 0};
long long int m = 0, n, res = 0, k, h;
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long int lcm(long long int x, long long int y) {
  return (x * y) / gcd(x, y);
}
string s2, ch = "", s, s1 = "", t;
vector<pair<string, long long int> > vm;
vector<pair<pair<long long int, long long int>, long long int> > vvvl, vvvr;
vector<pair<long long int, long long int> > vv, vv2;
vector<long long int> v[200005];
long long int a[2005][2005], b[2000];
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  long long int i = 0, x = 0, z = 0, y = 0, j = 0, q, mx = 0, idx = 0, ok = 0,
                l = 0, r = 0, negatif = 0, positif = 0, l1, r1, g = 0;
  set<long long int>::iterator it;
  cin >> n >> k;
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= n; j++) {
      if (i == j)
        cout << k << " ";
      else
        cout << "0 ";
    }
    cout << endl;
  }
  return 0;
}
