ave_koty

import datetime
import time

year_1 = int(input("Год: "))
month_1 = int(input("Месяц: "))
day_1 = int(input("День: "))

year_2 = int(input("Год: "))
month_2 = int(input("Месяц: "))
day_2 = int(input("День: "))

dr_1 = datetime.datetime(year_1, month_1, day_1)
dr_2 = datetime.datetime(year_2, month_2, day_2)

if dr_1 > dr_2:
    old = time.mktime(dr_1.timetuple()) 
    young = time.mktime(dr_2.timetuple()) 
elif dr_1 < dr_2:
    old = time.mktime(dr_2.timetuple()) 
    young = time.mktime(dr_1.timetuple()) 
else:
    print('Родились в одну дату')
    
day = datetime.date.fromtimestamp((old - young) * 2 + old)
print(day)