what will be the output :

#includeiostream
using namespace std;
class A
{
public:
    A()           { cout  "\n A's constructor"; }
    A(const A &a) { cout  "\n A's Copy constructor";  }
    A& operator= (const A &a)
    {
        if(this == &a) return *this;
        cout  "\n A's Assignment Operator";  return *this;
    }
};
class B
{
    A a;
public:
    B(A &a):a(a) {  cout  "\n B's constructor"; }
};
int main()
{
    A a;
    B b(a);
    return 0;
}