CPP Reference

#include<iostream>
using namespace std;
int main(){
-int a = 50;
-int *p = &a;
-int **p2 = &p;
-int ***p3 = &p2;
-int ****p4 = &p3;
-cout<<"----------------------"<<endl;
-cout<<"Pointers 1: "<<endl;
-cout<< (p4) <<endl;
-cout<< (*p4) <<endl;
-cout<< (**p4) <<endl;
-cout<< (***p4) <<endl;
-cout<< (****p4) <<endl;
-a = 90;
-cout<<"----------------------"<<endl;
-cout<<"Pointers 2: "<<endl;
-cout<< (p4) <<endl;
-cout<< (*p4) <<endl;
-cout<< (**p4) <<endl;
-cout<< (***p4) <<endl;
-cout<< (****p4) <<endl;
-a = 50;
-int &r = a;
-int &r2 = r;
-int &r3 = r2;
-int &r4 = r3;
-cout<<"----------------------"<<endl;
-cout<<"Reference 1: "<<endl;
-cout<< r <<" "<< r2 <<" "<<r3<<" "<< r4<<endl;
-a = 90;
-cout<<"----------------------"<<endl;
-cout<<"Reference 2: "<<endl;
-cout<< r <<" "<< r2 <<" "<<r3<<" "<< r4<<endl;
}