#include <bits/stdc++.h>
using namespace std;
using uint = unsigned int;
using lint = long long int;
using ulint = unsigned long long int;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;
template<class T, class U> void assign(V<T>& v, int n, const U& a) { v.assign(n, a); }
template<class T, class... Args> void assign(V<T>& v, int n, const Args&... args) { v.resize(n); for (auto&& e : v) assign(e, args...); }


int main() {
  cin.tie(nullptr); ios_base::sync_with_stdio(false);
  string s; cin >> s;
  int n = s.size();
  string res;
  for (int i = 0; i < n; ++i) {
    res += s[n - 1 - i];
    if (i != n - 1 and i % 3 == 2) res += ',';
  }
  reverse(begin(res), end(res));
  cout << res << '\n';
}