#include <stdio.h>

void wissel(int a, int b) {
    int hulpje = a;
    a = b;
    b = hulpje;
}

int main(void) {
    int x = 7, y = 8;
    printf("x = %d en y = %d\n", x, y);
    wissel(x, y);
    printf("x = %d en y = %d\n", x, y);
    getchar();
    return 0;
}