#include <stdio.h>

void
swap(int *a, int *b)
{
    int tmp;
    tmp = *a;
    *a = *b;
    *b = tmp;
}

int
main(void)
{
    int u, v;

    u = 2; v = 3;
    printf("u=%d v=%d\n", u, v);
    swap(&u, &v);
    printf("u=%d v=%d\n", u, v);

    return 0;
}