Division of the Treasure

The pirates have successfully divided a treasure of m gold coins among themselves, with each pirate receiving a share based on their rank and experience. The youngest pirate took one coin, and each following pirate took one more coin than the pirate before them. After the last pirate received their share, n coins remained, which were set aside for future use.

Determine the total number of pirates.

Input

Two natural numbers m and n are provided (1 ≤ n < m ≤ 10^6).

Output

Print the total number of pirates.

Examples