The number of even n-digit numbers 3

Determine and output the count of even natural numbers with exactly n digits that fall within the interval [a, b].

Input

You will receive three natural numbers: n, a, and b, all on a single line separated by spaces (1 ≤ n ≤ 12, 1 ≤ a, b ≤ 10^12).

Output

Provide the solution to the problem.

Examples