#include <bits/stdc++.h>
using namespace std;
int main() {
  string word, s;
  cin >> word;
  int len = word.length();
  for (int i = 0; i < len; i++) {
    if (word[i] == 'a' || word[i] == 'e' || word[i] == 'i' || word[i] == 'o' ||
        word[i] == 'u' || word[i] == 'A' || word[i] == 'E' || word[i] == 'I' ||
        word[i] == 'O' || word[i] == 'U' || word[i] == 'y' || word[i] == 'Y') {
      continue;
    } else {
      s += '.';
      s += tolower(word[i]);
    }
  }
  cout << s << endl;
}
