#include <bits/stdc++.h>
using namespace std;

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