#include <stdio.h>

void exchange(int *p1, int *p2, int *p3);


int main(void){

	int a, b, c;
	int *pa, *pb, *pc;

	printf("a?>>");
	scanf("%d", &a);
	printf("b?>>");
	scanf("%d", &b);
	printf("c?>>");
	scanf("%d", &c);

	pa = &a;
	pb = &b;
	pc = &c;

	exchange(pa, pb, pc);

	printf("a=%d b=%d c=%d", a, b, c);

	return 0;
}

void exchange(int *p1, int *p2, int *p3){
	int c;
	int *pc;
	pc = &c;

	if (*p1 > *p2){
		*pc = *p1;
		*p1 = *p2;
		*p2 = *pc;
	}
	if (*p1 > *p3){
		*pc = *p1;
		*p1 = *p3;
		*p3 = *pc;
	}
	if (*p2 > *p3){
		*pc = *p2;
		*p2 = *p3;
		*p3 = *pc;
	}
}