h3.c

#include 

int main(void)
{
	int i, j, num, bit ,length;
	printf("please input num: ");
	scanf("%d", &num);
	printf("please input bit: ");
	scanf("%d", &bit);
	printf("please input length: ");
	scanf("%d", &length);

	i = (((1 << length) - 1) << (bit -length + 1)) ^ num ;

	printf("The bit is: %x \n", i);

	return 0;
}