#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
#include <regex>

using namespace std;

#define REP(i,n) for(int i = 0; i < (n); ++i)
#define P(x) cout << (x) << "\n"
#define D(x) cerr << (x) << "\n"
#define fcout cout << fixed << setprecision(18)

using i64=long long int; // 10^18

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    string n;cin>>n;
    string r = regex_replace(n, regex("(\\d)(?=(\\d{3})+$)"), "$1,");
    P(r);
    return 0;
}