#include <bits/stdc++.h>
using namespace std;
int n;
char s[105][105];
char t[105];
bool judge1() {
  int i = 0;
  for (; i < n; i++) t[i] = 'E';
  t[i] = '\0';
  for (int i = 0; i < n; i++)
    if (strcmp(t, s[i]) == 0) return 1;
  return 0;
}
bool judge2() {
  for (int i = 0; i < n; i++) {
    int F = 1;
    for (int j = 0; j < n; j++)
      if (s[j][i] != 'E') {
        F = 0;
        break;
      }
    if (F) return 1;
  }
  return 0;
}
int main() {
  while (~scanf("%d", &n)) {
    for (int i = 0; i < n; i++) scanf("%s", s[i]);
    if (judge1() && judge2()) {
      cout << -1 << endl;
      continue;
    }
    if (judge1()) {
      for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++)
          if (s[j][i] == '.') {
            cout << j + 1 << " " << i + 1 << endl;
            break;
          }
      }
    } else
      for (int i = 0; i < n; i++) {
        int l = strlen(s[i]);
        for (int j = 0; j < l; j++)
          if (s[i][j] == '.') {
            cout << i + 1 << " " << j + 1 << endl;
            break;
          }
      }
  }
  return 0;
}
