constant in nested class in template class

[kedaman]

I want to put constants in a nested class of a parameterized class like this:

template<class x> class borka {
public:
    class borkb {
    public:
        static const int a;
    };

    static const a;
};

template<class x> const int borka<x>::a = 44; 
template<class x> const int borka<x>::borkb::a = 44;

int main(){
    cout << borka<int>::borkb::a << endl;
    cout << borka<int>::a << endl;
return 0;
}; 

And I get a link error in the nested class constant:
LNK2001: unresolved external symbol "public: static int const borka<int>::borkb::a" (?a@borkb@?$borka@H@@2HB)
Help anyone?