#include <boost/filesystem/convenience.hpp>

using namespace boost::filesystem;

#include <iostream>
using namespace std;

int main()
{
    try {
        create_directories("a");
        create_directories("1/2/3");
        create_directories("1/2/3");
    }
    catch(exception& e)
    {
        cout << e.what() << "\n";
    }
}