from datetime import date

user_name = input("What's your name? ")
user_age = input("Hi, " + user_name + ", what's your age? ")
user_age = int(user_age)

age_diff = 100 - user_age
current_year = date.today().year
future_year = current_year + age_diff

print("You will turn 100 in " + str(future_year))