#include <bits/stdc++.h>
using namespace std;
int main() {
  string C;
  cin >> C;
  transform(C.begin(), C.end(), C.begin(), ::tolower);
  for (int i = 0; i < C.length(); i++) {
    if (C[i] != 'a' && C[i] != 'o' && C[i] != 'e' && C[i] != 'i' &&
        C[i] != 'u' && C[i] != 'y') {
      cout << "." << C[i];
    }
  }
  return 0;
}
