while 语句的逻辑

# i =3
# username = '大天天'
# password = 123
# while i > 0:
#     name = input('请输入你的名字：')
#     i -= 1
#     if name==username:
#         pwd = int(input('请输入你的密码：'))
#         if pwd == password:
#             print('登录成功，请稍后:')
#             print('''恭喜你登陆成功！
#             欢迎用户进入
#             username:%s
#             password:%d
#             ''' %(name,pwd))
#             break
#         else:
#             print('你的密码错误:')
#             print('你还有%d次机会'%(i))
#             #continue#与下面if的用法 tab的变化
#         if i == 0:#按向左一个tab后变化
#             print('你的机会已经用完，结束本次操作')
#             # break#不要也是一样的作用
#     else:
#         print('你的用户名错误！请重新输入')
#         print('你还有%d次机会' %(i))
# i = 3
# username ='天'
# password =123
# while i > 0:
#     name = input('请输入你的用户名')
#     i -=1
#     if name == username:
#         pwd =int(input('请输入你密码'))
#         # print('请输入密码')
#         if pwd ==password :
#             print('登录成功')
#             print('''
#             name:%s
#             pwd:%d
#             ''' %(name,password))
#             break
#         else:
#             print('密码错误，请重新输入')
#             print('你还有%d次机会' %(i))
#             if i ==0:
#                 print('你的机会已经用完')
#     else:
#         print('用户名错误，请重新输入用户')
#         print('你还有%d次机会' %(i))
# i = 3
# username = '大天天'
# password = 123
# while i > 0:
#     name = input('请输入你名字:')
#     i -=1
#     if name == username:
#         pwd = int(input('请输入你的密码:'))
#         if pwd == 123:
#             print('登陆成功')
#             print('''
#             欢迎你登陆成功
#             name:%s
#             pwd:%d
#             ''' %(name,pwd))
#             break
#         else:
#             print('请重新输入密码')
#             print('你还有%d次机会' %(i))
#             # continue
#         if i == 0:
#                 print('您的机会已经用完，请结束本次操作')
#     else:
#         print('你的用户名错误，请重新输入')
#         print('你还有%d次机会' %(i))
# 输入一百以内的数
# i = 1
# while i <=100:
#     print(i)
#     i +=1

# i = 1
# sum =0
# while i <99:
#     if i % 2 != 0:
#         sum = sum + i
#     else:
#         sum = sum - i
#     i += 1
#     print(sum)
i = 0
j = -1
sum = 0
while i < 100:
    i +=1
    j = -j
    if i == 88:
       continue
    else:
        sum = sum + i*j
print(sum)