#include <stdio.h>
int main() {
int num = 42;
int *ptr1 = # // Declare and initialize a pointer to an integer.
int ptr2 = &ptr1; // Declare and initialize a pointer to a pointer to an integer.
printf("Value of num: %d\n", num);
printf("Value pointed to by ptr1: %d\n", *ptr1);
printf("Value pointed to by ptr2: %d\n", ptr2);
*ptr1 = 100; // Dereference ptr1 and assign a new value to the variable num.
printf("New value of num: %d\n", num);
printf("Updated value pointed to by ptr1: %d\n", *ptr1);
printf("Updated value pointed to by ptr2: %d\n", ptr2);
return 0;
}