#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    string s;
    cin >> s;
    int n = s.size();
    int nn = 0;
    rep(i,n){
        cout << s[i];
        nn--;
        if(nn > 0 && nn % 3 == 0)cout << ',';
    }
    cout << endl;

    return 0;
}