Program : constructor, destructor in multilevel inheritance

#include<iostream.h>
#include<conio.h>
class base
{
protected:
int a;
public:
base(int x)
{
a=x;
cout<<"Inside base constructor"<<endl;
}
~base()
{
cout<<"Inside base destructor"<<endl;
}
};//end of base class


class derived1 : public base
{
protected:
int b;
public:
derived1(int x,int y):base(x)
{
b=y;
cout<<"Inside derived1 constructor"<<endl;
}
~derived1()
{
cout<<"Inside derived1 destructor"<<endl;
}
};//end of derived class
class derived2 : public derived1
{
int c;
public:
derived2(int x,int y,int z):derived1(x,y)
{
c=z;
cout<<"Inside derived2 constructor"<<endl;
}
~derived2()
{
cout<<"Inside derived2 destructor"<<endl;
}
void show()
{
    cout<<"a : "<<a<<" "<<"b : "<<b<<"  "<<"c : "<<c<<endl;
}
};//end of derived class
void main()
{
clrscr();
derived2 obj(3,4,5);
obj.show();
}
/*
Inside base constructor
Inside derived1 constructor
Inside derived2 constructor
a : 3 b : 4  c : 5
Inside derived2 destructor
Inside derived1 destructor
Inside base destructor
*/