#330. How many numbers in [a, b] are divisible by 3?
You get a and b (a ≤ b). How many numbers from a to b (both included) can be divided by 3?
### Input
One line: a b (1 ≤ a ≤ b ≤ 10000).
### Output
One integer.
Examples
Input
3112 5065
Output
651
Input
3869 9053
Output
1728
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.