#include <string>
#include <sstream>
using namespace std;

class LabelManager{
public:
    LabelManager();

    string make_unique();

private:
    unsigned i;
};

LabelManager::LabelManager():i(0){}
   
string LabelManager::make_unique(){
    ostringstream out;
    out<<"L"<<i++;
    return out.str();
}