#include <iostream>
#include <string>

int main()
{
    std::string in;
    std::cin >> in;
    
    int count = 0;
    
    for(auto it = in.end() - 1; it != in.begin(); --it)
    {
        if(count == 2)
        {
           in.insert(it, ',');
        }
        count++;
        count = count >= 3 ? 0 : count;
    }
    
    std::cout << in << std::endl;
    return 0;
}