#include <bits/stdc++.h>
#define INF 990000000
//19
using namespace std;

int main() {

string n;

cin>>n;
int am=(int)n.size()%3;
//cout << am<<endl;
for(int i=0;i<(int)n.size();i++){
if(i==am && i!=0){
cout << ",";
am+=3;
}
if(i==0 && am==0)am+=3;
cout << n[i];

}




}