year = input('请输入一个年份：')

while not year.isdigit():
    year = input("抱歉，您的输入有误，请输入一个整数：")


year = int(year)
if year % 400:
    print(year, '是闰年')

else:
    if year % 4 and year % 100 != 0:
        print(year, '是闰年')

    else:
        print(year, '不是闰年')

