Universal Cup Judging System

Universal Cup

実行時間制限: 3 s メモリ制限: 1024 MB 満点: 100 難易度: [表示]
統計

给定一个正整数 $x$,求最小的正整数 $y$,使得 $x+y$ 的进位次数恰好为 $k$。

我们使用小学数学中学习的十进制列竖式加法来计算进位。例如,在下面的加法中,共有两次进位。

输入格式

第一行包含一个整数 $T$ ($1 \le T \le 10^5$),表示测试用例的数量。

对于每个测试用例,第一行包含两个整数 $x, k$ ($1 \le x < 10^{18}, 0 \le k \le 18$)。

输出格式

对于每个测试用例,输出一行,表示答案。如果不存在这样的 $y$,则输出 $-1$。

样例

输入格式 1

4
12345678 0
12345678 5
12345678 18
990099 5

输出格式 1

1
54322
999999999987654322
9910

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