Description

Calculate the sum of all odd numbers between non-negative integers m and n (inclusive), where m ≤ n and n ≤ 300. For example, if m = 3 and n = 12, the sum would be: 3 + 5 + 7 + 9 + 11 = 35.

Input Format

Two numbers, m and n, separated by a single space, where 0 ≤ m ≤ n ≤ 300.

Output Format

Output a single line containing an integer, representing the sum of all odd numbers between m and n (inclusive).

7 15

55