#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;cin>>n;
    vector<int> v;
    while(n>0){
        int a=n%10;
        v.push_back(a);
        n/=10;
    }
    for(int i=v.size()-1;i>=0;i--){
        cout<<v[i];
        if(i%3==0&&i!=0)cout<<",";
        
    }
    cout<<endl;
}