4. 输入年月日并判断输出这是当年的第几天。
nian=int(input("年："))
yue=int(input("月："))
ri=int(input("日："))
list=[31,60,91,121,152,182,213,244,274,305,335,366]

if yue==1:
count=ri
if (nian%4==0 and nian%100!=0)or nian%400==0:
if yue>1 and yue<13:
count=list[yue-2]+ri
else:
if yue>1 and yue<13:
count=list[yue-2]+yue-1
print("第"+str(count)+"天")