#include <bits/stdc++.h>
using namespace std;
bool isvovel(char ch) {
  if (ch == 'a' || ch == 'A' || ch == 'e' || ch == 'E' || ch == 'i' ||
      ch == 'I' || ch == 'o' || ch == 'O' || ch == 'u' || ch == 'U' ||
      ch == 'y' || ch == 'Y')
    return true;
  return false;
}
int main() {
  string str;
  cin >> str;
  string ans = "";
  for (int i = 0; i < str.length(); i++) {
    char ch = str[i];
    if (!isvovel(ch)) {
      ans += '.';
      if (ch < 97) {
        ans += (ch + 32);
      } else {
        ans += ch;
      }
    }
  }
  cout << ans << endl;
  return 0;
}
