#include<stdio.h>
void main(void)
{
	int length;
	length=sizeof(stdin);
	printf("stdin length=%d\n",length);

	length=sizeof(stdout);
	printf("stdout length=%d\n",length);
	
}
/*These pointers can be used as arguments to functions. Some functions, 
such as getchar and putchar, use stdin and stdout automatically.*/