When going for a run, Rita takes her phone to listen to music and wireless headphones. Before every run, Rita charges her headphones, and this charge is enough for A minutes of listening to music. Rita decided that every day she would train for a minute longer than the previous day. That is, if on the first day Rita ran and listened to music for B & nbsp; minutes, on the second day she will run B + 1 minute, on the third day — B + 2 minutes, etc.
If the earbuds last more than the duration of the run, the unused charge accumulates and can be used in the following days. The headphone battery capacity can be considered unlimited.
Find out on which day Rita will first run out of power to listen to music during her entire run.
Input
The first line of the input contains an integer A (1 <= A <= 10
9 ) — amount of daily battery charge (in minutes of listening to music). The second line of the input contains an integer B (1 <= B <= 10
9 ) — duration of the run on the first day.
Imprint
The program should output a single integer — the number of the day that Rita is missing for the first time
charge your headphones for the whole run
Examples