#include <stdio.h>

void swap (int *px, int *py){
	int temp;
	temp = *px;
	*px = *py;
	*py = temp;
}

int main(){
	int x = 3;
	int y = 5;

	printf ("x = %d, y = %d \n",x,y);
	swap (&x, &y);
	printf ("x = %d, y = %d \n",x,y);
}