#include <bits/stdc++.h>
using namespace std;
int main(void){
    int n;
    string s;
    cin>>s;
    n=s.length()%3;
    for(int i=0;i<s.length();i++){
        if(i==0){
            cout<<s[i];
            continue;
        }
        if(i%3==n) cout<<",";
        cout<<s[i];
    }
    cout<<"\n";
}