#include <stdio.h>

struct A {
  struct A * first;
  int value;
};

int main () {
  struct A a = { &a };
  a.first -> value = 123;

  static struct A b = { &b };
  b.first -> value = 456;

  printf("&a = %p, a.first = %p\n", &a, a.first);
  printf("&b = %p, b.first = %p\n", &b, b.first);
}