#include <stdio.h>

void swap(int*x, int*y){
    int tmp = *y;
    *y = *x;
    *x = tmp;
}

int main() {
    int x = 100;
    int y = 200;
    
    swap(&x, &y);
    printf("x=%d, y=%d\n", x,y);
    return 0;
}