#313. How many numbers in [a, b] are divisible by 2?
You get a and b (a ≤ b). How many numbers from a to b (both included) can be divided by 2?
### Input
One line: a b (1 ≤ a ≤ b ≤ 10000).
### Output
One integer.
Examples
Input
1937 5452
Output
1758
Input
2615 7394
Output
2390
💡 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.