#include <stdio.h>

void func(int *pa, int *pb, int a, int b)
{
	*pa = b;
	*pb = a;
	}
int main(void) {
	int a = 5;
	int b = 7;
	printf("a: %d, b:%d\n",a,b);
	func(&a,&b,a,b);
	puts("swap");
	printf("a: %d, b:%d\n",a,b);
	return 0;
}