Problems > Count Triangulars in a Range

Count Triangulars in a Range

Difficulty: 1200 2000 ms 128 MB

math

How many triangular numbers (1, 3, 6, 10, ...) lie in [L, R]?

Input: one line with two integers L and R.

Output: the count of such numbers in the range.

Constraints:

  • 1 ≤ L ≤ R ≤ 1018

Sample Tests

Input 1
1 20
Output 1
5
Input 2
5 5
Output 2
0

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