Sum of Leap Years Excluding Boundaries

Given two years, compute the sum of all leap years strictly between them (i.e., not including the starting year and the terminal year).

A year is considered a leap year if it satisfies the following condition: \( (\text{year} \bmod 4 = 0 \text{ and } \text{year} \bmod 100 \neq 0) \) or \( \text{year} \bmod 400 = 0 \).

inputFormat

The input consists of two integers separated by a space representing the starting year and the ending year.

outputFormat

Output the sum of all leap years strictly between the two given years.

sample

2000 2020

8040