Odd sum

For a given interval, give the sum of all odd numbers in the interval.

Source: https://onlinejudge.org/external/107/10783.pdf

Specification

Input

• \(a, b\) - integers in the interval \([0,100]\)

Output

• The sum of all odd numbers in the interval \([a,b]\)

Example

Input

3 9

Output

24

Info

Explanation

\(3+5+7+9=24\)