adding abcd

lectures/26_inheritance/ABCD.cpp

@@ -0,0 +1,28 @@
+class A
+{
+public:
+	A(int a):a(a){}
+	int a;
+};
+class B:public A
+{
+public:
+	B(int a, int b):b(b),A(a){}
+	int b;
+};
+class C:public B
+{
+public:
+	C(int a, int b, int c):B(a, b),c(c){}
+	int c;
+
+};
+class D:public C
+{
+public:
+	int d;
+};
+
+int main(){
+	return 0;
+}