#include <iostream>
#include <string>

using namespace std;

int main(){
	char number[20];
	int i=0,len=0;

	cin>>number;

	while(number[len]>='0'){
		len++;
	}

	while(len!=0){
		cout<<number[i];
		len--;
		i++;
		if(len%3==0 && len>0){
			cout<<',';
		}
	}

	cout<<"\n";

	return 0;
}