# Olesya and Rodion

## 题意翻译

**题目大意**
找到一个n位数使其能被t整除。
**输出**
如果有多个解，输出一个。如果没有解，输出“-1”。

## 题目描述

Olesya loves numbers consisting of $ n $ digits, and Rodion only likes numbers that are divisible by $ t $ . Find some number that satisfies both of them.
Your task is: given the $ n $ and $ t $ print an integer strictly larger than zero consisting of $ n $ digits that is divisible by $ t $ . If such number doesn't exist, print $ -1 $ .

## 输入输出格式

### 输入格式

The single line contains two numbers, $ n $ and $ t $ ( $ 1<=n<=100 $ , $ 2<=t<=10 $ ) — the length of the number and the number it should be divisible by.

### 输出格式

Print one such positive number without leading zeroes, — the answer to the problem, or $ -1 $ , if such number doesn't exist. If there are multiple possible answers, you are allowed to print any of them.

## 输入输出样例

### 输入样例 #1

```
3 2
```

### 输出样例 #1

`712`