#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, m;
  cin >> n >> m;
  long long int k = n * m;
  long long int arr[k + 1];
  arr[0] = -1;
  map<long long int, long long int> mp1;
  long long int t = 0, sum = 0;
  for (long long int i = 1; i <= k; i++) {
    cin >> arr[i];
    if (arr[i] == 1)
      mp1[i] = 8;
    else
      t++;
  }
  if (t == k) {
    cout << "0";
    return 0;
  }
  long long int p = k - m, x, c = 0;
  vector<long long int> v;
  map<long long int, long long int> mp;
  for (long long int i = 1; i < p; i++) {
    if (arr[i] == 1 && i % m != 0) {
      x = m * ((i / m) + 1) + (i % m);
      if (arr[i + 1] == 1 && arr[x] == 1 && arr[x + 1] == 1) {
        mp[i] = 8;
        mp[i + 1] = 8;
        mp[x] = 8;
        mp[x + 1] = 8;
        sum += 4;
        v.push_back(i);
        c++;
      }
    }
  }
  sum = mp.size();
  long long int t1 = mp1.size();
  if (sum != t1)
    cout << "-1";
  else {
    cout << c << "\n";
    for (long long int i = 0; i < v.size(); i++) {
      cout << (v[i] / m) + 1 << " " << (v[i] % m) << "\n";
    }
  }
}
