#include <stdio.h>


int a;

void f()
{
   printf("a at start of f = %d\n", a);

   a = a + 4;

   printf("a at end of f = %d\n", a);
}

void g()
{
   int x = 0;
}

int main( int argc, char *argv[] )
{

    a = 1;

    printf("------------------\n");
    printf("Invocation 1:\n");
    f();
    g();

    printf("------------------\n");
    printf("Invocation 2:\n");
    f();
    g();

    printf("------------------\n");
    printf("Invocation 3:\n");
    f();
    g();

    printf("------------------\n");
}