#include <iostream>
#include <string>

int main() {
    int i, j, n;
    std::string ans;
    std::cin >> n;
    while (true) {
        j = n % 10;
        n /= 10;
        ans = std::to_string(j) + ans;
        if ((i != 0) && (i % 3 == 0)) {
            ans = "," + ans;
        }
        i += 1;
        if (n <= 0) {
            break;
        }
    }
    std::cout << ans << std::endl;
    return 0;
}