C++ how to allocate memory to a pointer of a struct which is member of another second struct?

This is the code:

# include<iostream>
#include<stdio.h>
using namespace std;
    struct hub
    {
        int info;
        int info2;
    };
    struct hub2
    {
        hub *p;
    };
    int main()
    {
        hub *pi;
        pi = new hub; // allocate memory for pi
        pi->info = 30;
        pi->info2 = 45;
        cout<<pi->info<<" "<<pi->info2; // shows 30 and 45
        hub2 obj; // declare a hub2 data type
        obj.p = new hub; // allocate memory for obj.p
        obj.p = pi; // now obj.p should be identical to what pi points to right?
        cout<<"\n"<<obj.p->info<<" "<<obj.p->info2; // This will show 30 and 45
        cout<<endl;
        delete pi;
        cout<<"\n"<<obj.p->info<<" "<<obj.p->info2;//This shows random numbers,why ???
    }

Why doesn't obj.p allocate memory after I delete the memory allocated for pi pointer? I really need a solution to this.I have to finish a very important project and I am stuck here with at this memory allocating part :(