#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> v;
int res;
int countOne(vector<vector<int>> &a, int i, int j) {
  int res = 0;
  if (a[i][j] == 1) res++;
  if (a[i + 1][j] == 1) res++;
  if (a[i][j + 1] == 1) res++;
  if (a[i + 1][j + 1] == 1) res++;
  return res;
}
void switchZeroOne(vector<vector<int>> &a, int i, int j) {
  int cnt = countOne(a, i, j);
  while (cnt != 0) {
    if (cnt == 4) {
      v[res].push_back(i);
      v[res].push_back(j);
      v[res].push_back(i);
      v[res].push_back(j + 1);
      v[res].push_back(i + 1);
      v[res].push_back(j);
      res++;
      a[i][j] = 0;
      a[i][j + 1] = 0;
      a[i + 1][j] = 0;
      cnt = 1;
    } else if (cnt == 1) {
      int switchZero = 0;
      for (int x = i; x < i + 2; x++) {
        for (int y = j; y < j + 2; y++) {
          if (a[x][y] == 1) {
            a[x][y] = 0;
            v[res].push_back(x);
            v[res].push_back(y);
          } else if (switchZero < 2) {
            a[x][y] = 1;
            v[res].push_back(x);
            v[res].push_back(y);
            switchZero++;
          }
        }
      }
      res++;
      cnt = 2;
    } else if (cnt == 2) {
      int switchOne = 0;
      for (int x = i; x < i + 2; x++) {
        for (int y = j; y < j + 2; y++) {
          if (a[x][y] == 0) {
            a[x][y] = 1;
            v[res].push_back(x);
            v[res].push_back(y);
          } else if (switchOne < 1) {
            a[x][y] = 0;
            v[res].push_back(x);
            v[res].push_back(y);
            switchOne++;
          }
        }
      }
      res++;
      cnt = 3;
    } else if (cnt == 3) {
      for (int x = i; x < i + 2; x++) {
        for (int y = j; y < j + 2; y++) {
          if (a[x][y] == 1) {
            a[x][y] = 0;
            v[res].push_back(x);
            v[res].push_back(y);
          }
        }
      }
      res++;
      cnt = 0;
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t, n, m;
  string s;
  cin >> t;
  while (t--) {
    cin >> n >> m;
    vector<vector<int>> a(n + 1, vector<int>(m + 1));
    for (int i = 1; i <= n; i++) {
      cin >> s;
      for (int j = 1; j <= m; j++) {
        a[i][j] = s[j - 1] - '0';
      }
    }
    v = vector<vector<int>>(50000);
    res = 0;
    if (n > 2) {
      for (int i = 1; i <= n - 2; i++) {
        for (int j = 1; j <= m - 1; j++) {
          if (a[i][j] == 1 && a[i][j + 1] == 1) {
            v[res].push_back(i);
            v[res].push_back(j);
            v[res].push_back(i);
            v[res].push_back(j + 1);
            v[res].push_back(i + 1);
            v[res].push_back(j);
            res++;
            a[i][j] = 0;
            a[i][j + 1] = 0;
            a[i + 1][j] ^= 1;
          } else if (a[i][j] == 1) {
            v[res].push_back(i);
            v[res].push_back(j);
            v[res].push_back(i + 1);
            v[res].push_back(j);
            v[res].push_back(i + 1);
            v[res].push_back(j + 1);
            res++;
            a[i][j] = 0;
            a[i + 1][j] ^= 1;
            a[i + 1][j + 1] ^= 1;
          } else if (a[i][j + 1] == 1) {
            v[res].push_back(i);
            v[res].push_back(j + 1);
            v[res].push_back(i + 1);
            v[res].push_back(j);
            v[res].push_back(i + 1);
            v[res].push_back(j + 1);
            res++;
            a[i][j + 1] = 0;
            a[i + 1][j] ^= 1;
            a[i + 1][j + 1] ^= 1;
          }
        }
      }
      for (int j = 1; j <= m - 1; j += 2) {
        switchZeroOne(a, n - 1, j);
      }
      if (m % 2 == 1) switchZeroOne(a, n - 1, m - 1);
    } else {
      for (int j = 1; j <= m - 2; j++) {
        for (int i = 1; i <= n - 1; i++) {
          if (a[i][j] == 1 && a[i + 1][j] == 1) {
            v[res].push_back(i);
            v[res].push_back(j);
            v[res].push_back(i);
            v[res].push_back(j + 1);
            v[res].push_back(i + 1);
            v[res].push_back(j);
            res++;
            a[i][j] = 0;
            a[i][j + 1] ^= 1;
            a[i + 1][j] = 0;
          } else if (a[i][j] == 1) {
            v[res].push_back(i);
            v[res].push_back(j);
            v[res].push_back(i);
            v[res].push_back(j + 1);
            v[res].push_back(i + 1);
            v[res].push_back(j + 1);
            res++;
            a[i][j] = 0;
            a[i][j + 1] ^= 1;
            a[i + 1][j + 1] ^= 1;
          } else if (a[i + 1][j] == 1) {
            v[res].push_back(i);
            v[res].push_back(j + 1);
            v[res].push_back(i + 1);
            v[res].push_back(j);
            v[res].push_back(i + 1);
            v[res].push_back(j + 1);
            res++;
            a[i][j + 1] ^= 1;
            a[i + 1][j] = 0;
            a[i + 1][j + 1] ^= 1;
          }
        }
      }
      for (int i = 1; i <= n - 1; i += 2) {
        switchZeroOne(a, i, m - 1);
      }
      if (n % 2 == 1) switchZeroOne(a, n - 1, m - 1);
    }
    cout << res << "\n";
    for (int i = 0; i < res; i++) {
      for (int j = 0; j < v[i].size(); j++) {
        cout << v[i][j] << " ";
      }
      cout << "\n";
    }
  }
  return 0;
}
