Yura decided to prepare for the regional Olympiad in Informatics. He chose N problems on the site informatics.mccme.ru to solve them during the holidays. On the first day Yura solved K problems, and on each next day Yura solved one more problem than on the previous day. Determine how many days it will take Yura to prepare for the Olympics.
The program receives as input two positive integers N and K, written in separate lines — the number of problems that Yura intends to solve, and the number of problems that he solved on the first day of training.
The program should output a single number — the number of days it took Yura to complete the tasks.
In the example, on the first day Yura will solve 3 problems, on the second day — 4, on the third day — 5, in total it will take Yura 3 days to solve 10 problems.