Sum of Digits

题意翻译

令 $f(x)$ 表示一个十进制整数 $x$ 每个数位的数字之和。 给定 $n, k$，求出最小的非负整数 $x$，使得 $f(x) + f(x + 1) + \cdots + f(x + k) = n$。 无解输出 `-1`。

题目描述

Let $ f(x) $ be the sum of digits of a decimal number $ x $ . Find the smallest non-negative integer $ x $ such that $ f(x) + f(x + 1) + \dots + f(x + k) = n $ .

输入输出格式

输入格式

The first line contains one integer $ t $ ( $ 1 \le t \le 150 $ ) — the number of test cases. Each test case consists of one line containing two integers $ n $ and $ k $ ( $ 1 \le n \le 150 $ , $ 0 \le k \le 9 $ ).

输出格式

For each test case, print one integer without leading zeroes. If there is no such $ x $ that $ f(x) + f(x + 1) + \dots + f(x + k) = n $ , print $ -1 $ ; otherwise, print the minimum $ x $ meeting that constraint.

输入输出样例

输入样例 #1

7
1 0
1 1
42 7
13 7
99 1
99 0
99 2

输出样例 #1

1
0
4
-1
599998
99999999999
7997