The number of even n-digit numbers is 4

It is necessary to find and output the number of even natural $n$ significant numbers that do not belong to the interval $[a,b]$.

Input

Three natural numbers $n$, $a$, $b$ in one line separated by a gap $(1\le n\le 12)$, $(1\le a,b\le 10^{1}2)$

Output

The answer to the problem.

Examples