#include <bits/stdc++.h>
using namespace std;
long long int power(long long int x, long long int n) {
  long long int result = 1;
  while (n) {
    if (n % 2 == 1) result = result * x;
    n = n / 2;
    x = x * x;
  }
  return result;
}
long long int gcd(long long int a, long long int b) {
  if (!b) return a;
  return gcd(b, a % b);
}
long long int lcm(long long int a, long long int b) {
  return (a * b) / gcd(a, b);
}
long long int bsearch(long long int a[], long long int s, long long int n,
                      long long int val) {
  long long int mid, beg = s, end = n - 1;
  while (beg <= end) {
    mid = (beg + end) / 2;
    if (val == a[mid]) {
      break;
    } else if (val > a[mid]) {
      beg = mid + 1;
    } else {
      end = mid - 1;
    }
  }
  return mid;
}
long long int max_sum_subarray(long long int a[], long long int n) {
  long long int max = 0, s = 0, f = 0, sum = 0, maxs = 0, maxf = 0;
  for (f = 0; f < n; f++) {
    sum += a[f];
    if (sum > max) {
      max = sum;
      maxs = s;
      maxf = f;
    }
    if (sum < 0) {
      sum = 0;
      s = f + 1;
    }
  }
  return max;
}
vector<long long int> prime;
void prime_num(long long int n) {
  vector<long long int> v;
  long long int i, j;
  for (i = 0; i <= n; i++) v.push_back(i);
  v[0] = -1;
  v[1] = -1;
  for (i = 0; i <= sqrt(n); i++) {
    if (v[i] == -1) {
      continue;
    }
    for (j = i + i; j <= n; j += i) {
      v[j] = -1;
    }
  }
  for (i = 2; i <= n; i++) {
    if (v[i] != -1) {
      prime.push_back(i);
    }
  }
}
void io() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
int main() {
  io();
  long long int t;
  cin >> t;
  while (t--) {
    long long int n, k;
    cin >> n >> k;
    long long int a[n][n], i, j;
    for (i = 0; i < n; i++) {
      for (j = 0; j < n; j++) a[i][j] = 0;
    }
    if (k % n == 0) {
      cout << "0\n";
      for (i = 0; i < n; i++) {
        for (j = i; j < i + (k / n); j++) {
          a[i][j % n] = 1;
        }
      }
    } else {
      cout << "2\n";
      for (i = 0; i < n; i++) {
        for (j = i; j < i + (k / n); j++) {
          a[i][j % n] = 1;
        }
      }
      for (i = 0; i < k % n; i++) {
        a[i][(i + k / n) % n] = 1;
      }
    }
    for (i = 0; i < n; i++) {
      for (j = 0; j < n; j++) cout << a[i][j];
      cout << "\n";
    }
  }
  return 0;
}
