#include <stdio.h>
#include <stdlib.h>
int main()
{
  
  //通過位運算實現數字的反轉（操作的物件必須是整數）

  unsigned  int original =0x123;
  unsigned  int result  =0;
  unsigned  int mask =0xF;   //掩碼

  
  result |=original&mask;

  original>>=4;
  result<<=4;
  result |=original&mask;

  original>>=4;
  result<<=4;
  result|=original & mask;



  printf("%X\n",result);

  
 
	  
  return 0;
}