#include<stdio.h>

void swap();
int x,y;

int main(int argc, char **argv)
{

	x = 5; y = 9;
	printf("x = %d, y = %d\n",x,y);
	swap();
	printf("x = %d, y = %d\n",x,y);
}

void swap()
{
	int t;

	t = x;
	x = y;
	y = t;
}