import getpass
# user = input("username:")
# password = getpass.getpass(prompt="password:")
# print(user)
# print(password)
#getpass在pycharm内无效果
# i = 1
# while True:
# print(i)
# i += 1
# if i == 7:
# continue
# if i == 200:
# break
# def sum(number):
# result = (1 + number)*number/2
# return result
# print(sum(10000))
# def sum_1(number):
# if number%2 == 0:
# last_number = number-1
# else:
# last_number = number
# i = (last_number-1)/2+1
# result = (1 + last_number)*i/2
# return result
# print(sum_1(11))
# def sum_2(number):
# if number%2 == 0:
# last_number = number
# else:
# last_number = number -1
# i = (last_number-2)/2+1
# result = (2+last_number)*i/2
# return result
# print(sum_2(12))
# a_3 = sum_1(99)-sum_2(99)
# print(a_3)