Problem Statement

You are given positive integers $N$ and $M$. Find the maximum positive integer $X$ that satisfies all of the following conditions.

• $X$ is a positive integer less than $10^N$, and all digits in the decimal representation of $X$ are the same.
• $X$ is a multiple of $M$.

If no positive integer $X$ satisfies the conditions, print -1.

Constraints

• $1\leq N\leq 10^5$
• $1\leq M\leq 10^9$

Input

The input is given from Standard Input in the following format:

N M

Output

Print the maximum positive integer $X$ that satisfies all of the conditions, or -1 if no such positive integer $X$ exists.