#include <stdio.h>

void swap (int *a, int *b);

void swap (int *a, int *b)
{
    int t;
    printf("inside swap: %d   %d\n", *a, *b);

    t = *a;
    *a = *b;
    *b = t;
    printf("inside swap: %d   %d\n", *a, *b);
}
   
int main(void)
{
    int a = 5;
    int b = 6;

    printf("%d   %d\n", a, b);

    swap(&a, &b);

    printf("%d   %d\n", a, b);

    return 0;
}