#include <bits/stdc++.h>

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = std::int64_t;
using P = std::tuple<int,int>;

std::string N;

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    std::cin >> N;

    int len = N.size();
    for(int i=0;i<len;++i){
        std::cout << N[i];
        int j = len - 1 - i;
        if(j % 3 == 0 && j > 0){
            std::cout << ",";
        }
    }
    std::cout << std::endl;
}