#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0;i < (n); ++i)
typedef long long ll;

const int mod = 1e9+7;
const int INF = 2000000;
const double PI = acos(-1.0);

int main() {
    
    string N;
    cin >> N;
    string ans = "";
    int len = N.size();
    for(int i = 1; i <= len; ++i) {
        ans = N[len-i] + ans;
        if (i % 3 == 0 && i != len) ans = "," + ans;
    }
    cout << ans << endl;
}