#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;
}