A. A+B?
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Once, Maxim bet that he could come up with a problem with the shortest statement that could touch anyone's heart. He won the bet:

"For given numbers $$$n$$$ and $$$p$$$, calculate the number of possible pairs ($$$a, b$$$) such that $$$a + b = n$$$ and $$$-10^{p} \le a, b \le 10^{p}$$$."

Input

A single line contains two integers $$$n$$$ ($$$-2 \cdot 10^{9} \le n \le 2 \cdot 10^{9}$$$) and $$$p$$$ ($$$1 \le p \le 9$$$).

Output

Print a single integer – the answer to the problem.

Examples
Input
7 1
Output
14
Input
-4 1
Output
17
Input
25 1
Output
0