说明： 这是一个判断闰年的小程序，只要你随意输入一个年份，程序就会自动帮你算出是不是闰年，并显示结果给你看！ (This is a small leap year judgment procedures, as long as you can input a year, procedures will automatically help you calculate it is not a leap year, and the result will be displayed for you!)
