A year $Y$ is a leap year if $Y$ is a multiple of $4$. However, there is an exception: if $Y$ is a multiple of $100$ and not a multiple of $400$, it is not a leap year.

For example, 1900 is not a leap year, but 2000 is a leap year.

Given two integers $L$ and $R$, output the number of leap years between year $L$ and $R$ (inclusive).

Input

The only line of input contains two integers $L$ and $R$.

Output

Output the number of leap years between years $L$ and $R$.

Constraints

In all subtasks, $1 \le L \le R \le 10^9$
Subtask 1 (50%): $L = 1$
Subtask 2 (50%): No additional constraints