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

int main() {
  string N; cin >> N;
  int n = (int)N.size();
  if(n <= 3){
    cout << N << endl;
  }else{
    string ans = "";
    for(int i = 0; i < n; i++){
      ans += N[i];
      if((i+1)%3 == n%3) ans += ",";
    }
    ans.pop_back();
    cout << ans << endl;
  } 
}