In a restaurant, if you were pleased by the waiter's service, you may leave him a tip -- you pay him more than the actual value of the bill, and the waiter keeps the excess money. In some countries, not leaving a tip for the waiter is even considered impolite. During my recent holiday I was having dinner in a foreign restaurant. The pamphlet from my travel agency informed me that the proper way of tipping the waiter is the following:
Clearly, sometimes there may be multiple "correct" ways of settling the bill. I'd like to know exactly how many choices I have in a given situation. I could program it easily, but I was having a holiday... and so it's you who has to solve this task. You will be given:
Write a function that computes how many different final sums satisfy the conditions above.
4 100 Returns: 0
4 isn't a round sum, and 5 is too much.
23 100 Returns: 1
The only correct choice is to pay 25 dollars, thus leaving a tip of 2 dollars.
23 24 Returns: 0The same bill, but I don't have enough money to leave an appropriate tip.
220 239 Returns: 1This time, it is appropriate to pay either 235 or 240 dollars. Sadly, I don't have enough money for the second possibility.
1234567 12345678 Returns: 14440A large bill, but with that much money I don't care.
1880000000 1980000000 Returns: 210527
171000000 179999999 Returns: 0