#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const int inf = 1e9;
const int maxn = 200005;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t;
  cin >> t;
  while (t--) {
    int n, m;
    cin >> n >> m;
    vector<vector<int>> mat(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
      string s;
      cin >> s;
      for (int j = 0; j < m; j++) mat[i][j] = s[j] - '0';
    }
    vector<vector<int>> ans;
    for (int i = 0; i < n - 2; i++) {
      for (int j = 0; j < m - 1; j++) {
        if (mat[i][j] == 0) continue;
        ans.push_back({i, j});
        mat[i][j] ^= 1;
        ans.back().push_back(i + 1), ans.back().push_back(j);
        ans.back().push_back(i + 1), ans.back().push_back(j + 1);
        mat[i + 1][j] ^= 1;
        mat[i + 1][j + 1] ^= 1;
      }
      if (mat[i][m - 1]) {
        ans.push_back({i, m - 1});
        mat[i][m - 1] ^= 1;
        ans.back().push_back(i + 1), ans.back().push_back(m - 2);
        ans.back().push_back(i + 1), ans.back().push_back(m - 1);
        mat[i + 1][m - 2] ^= 1;
        mat[i + 1][m - 1] ^= 1;
      }
    }
    for (int j = 0; j < m - 2; j++) {
      if (mat[n - 1][j] == 0 && mat[n - 2][j] == 0) continue;
      int cont = 0;
      vector<int> tmp;
      if (mat[n - 2][j]) {
        cont++;
        mat[n - 2][j] ^= 1;
        tmp.push_back(n - 2), tmp.push_back(j);
      }
      if (mat[n - 1][j]) {
        cont++;
        mat[n - 1][j] ^= 1;
        tmp.push_back(n - 1), tmp.push_back(j);
      }
      cont++;
      mat[n - 2][j + 1] ^= 1;
      tmp.push_back(n - 2), tmp.push_back(j + 1);
      if (cont < 3) {
        cont++;
        mat[n - 1][j + 1] ^= 1;
        tmp.push_back(n - 1), tmp.push_back(j + 1);
      }
      ans.push_back(tmp);
    }
    auto move = [&](int i, int j) {
      vector<pair<int, pair<int, int>>> v;
      v.push_back({mat[i][j], {i, j}});
      v.push_back({mat[i][j + 1], {i, j + 1}});
      v.push_back({mat[i + 1][j], {i + 1, j}});
      v.push_back({mat[i + 1][j + 1], {i + 1, j + 1}});
      int cont = 0;
      for (int k = 0; k < 4; k++) cont += v[k].first;
      if (cont == 0) return;
      if (cont == 4) {
        sort((v).rbegin(), (v).rend());
        for (int k = 0; k < 3; k++) {
          v[k].first ^= 1;
          mat[v[k].second.first][v[k].second.second] ^= 1;
        }
        ans.push_back({v[0].second.first, v[0].second.second, v[1].second.first,
                       v[1].second.second, v[2].second.first,
                       v[2].second.second});
        cont = 1;
      }
      if (cont == 1) {
        sort((v).rbegin(), (v).rend());
        for (int k = 0; k < 3; k++) {
          v[k].first ^= 1;
          mat[v[k].second.first][v[k].second.second] ^= 1;
        }
        ans.push_back({v[0].second.first, v[0].second.second, v[1].second.first,
                       v[1].second.second, v[2].second.first,
                       v[2].second.second});
        cont++;
      }
      if (cont == 2) {
        sort((v).rbegin(), (v).rend());
        for (int k = 0; k < 1; k++) {
          v[k].first ^= 1;
          mat[v[k].second.first][v[k].second.second] ^= 1;
        }
        for (int k = 3; k >= 2; k--) {
          v[k].first ^= 1;
          mat[v[k].second.first][v[k].second.second] ^= 1;
        }
        ans.push_back({v[0].second.first, v[0].second.second, v[2].second.first,
                       v[2].second.second, v[3].second.first,
                       v[3].second.second});
        cont++;
      }
      if (cont == 3) {
        sort((v).rbegin(), (v).rend());
        for (int k = 0; k < 3; k++) {
          v[k].first ^= 1;
          mat[v[k].second.first][v[k].second.second] ^= 1;
        }
        ans.push_back({v[0].second.first, v[0].second.second, v[1].second.first,
                       v[1].second.second, v[2].second.first,
                       v[2].second.second});
        cont++;
      }
    };
    move(n - 2, m - 2);
    cout << ans.size() << '\n';
    for (auto &i : ans)
      for (auto &j : i) cout << j + 1 << " \n"[&j == &i.back()];
  }
  return 0;
}
