#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  string n;
  cin >> n;
  string ans = "";
  reverse(n.begin(), n.end());
  rep(i, n.size()) {
    ans.push_back(n[i]);
    if (i % 3 == 2) ans.push_back(',');
  }
  if (ans.back() == ',') ans.pop_back();
  reverse(ans.begin(), ans.end());
  cout << ans << endl;
  return 0;
}