reachin the class' properties from a class define in the former

Question

public class A { public A() { a=5; B theb=new B() } private int a; public int thea { get{return a;} set{a=value;} } public class B { public B(); public int b(int x) { //here i need to reach the property of class A } } how can i reach the value of thea property from the method defined inside the B which contained by A?