>>20
１
#include <stdio.h>

void exch_order(int *pa, int *pb) {
if(*pa>*pb)
{
int tmp=*pa;
*pa=*pb;
*pb=tmp;
}
}

int main(void) {
int a,b;
printf("Input > ");
scanf("%d %d",&a,&b);
exch_order(&a, &b);
printf("%d %d\n",a,b);
return 0;
}