#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
const ld eps = 1e-9;
const ll MOD = 1000000007;
const int INF = 1000000000;
const ll LINF = 1ll << 50;
template <typename T>
void printv(const vector<T>& s) {
  for (int i = 0; i < (int)(s.size()); ++i) {
    cout << s[i];
    if (i == (int)(s.size()) - 1)
      cout << endl;
    else
      cout << " ";
  }
}
template <typename T1, typename T2>
ostream& operator<<(ostream& os, const pair<T1, T2> p) {
  os << p.first << ":" << p.second;
  return os;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  int t;
  cin >> t;
  while (t) {
    t--;
    int n, m;
    cin >> n >> m;
    vector<string> ans(n);
    for (int i = 0; i < n; ++i) {
      for (int j = 0; j < m; ++j) {
        ans[i].push_back('W');
      }
    }
    for (int i = 0; i < n; ++i) {
      for (int j = 0; j < m; ++j) {
        if ((i + j) % 2 == 0) {
          ans[i][j] = 'B';
        }
      }
    }
    if (n * m % 2 == 0) {
      if (n != 1)
        ans[1][0] = 'B';
      else
        ans[0][1] = 'B';
    }
    for (int i = 0; i < n; ++i) {
      cout << ans[i] << endl;
    }
  }
}
