Puzzle SL24

Rule 2.1, 2.2, and 2.4

What does the following code write to the monitor?

---

/* --- fileA.c --- */
int x = 8;

---

/* --- fileB.c --- */
void foo()
{
  extern int x;
  x = 99;
}

---

/* --- fileC.c --- */
#include <stdio.h>
void foo();

int x;
void main()
{
  foo();
  printf("%d\n", x );
}

---

Note that extern has been removed from one of the declarations.