#include <iostream>
#include <string>

int main() {
  std::string N;
  std::cin >> N;
  for (int i  = 0; i < N.size(); ++i) {
    std::cout << N[i];
    int res = N.size() - (i + 1);
    if (res != 0 && res != N.size() && res % 3 == 0) {
      std::cout << ",";
    }
  }
  std::cout << std::endl;
  return 0;
}