{"raw_statement":[{"iden":"statement","content":"Given a positive integer $x$, find the minimum positive integer $y$ such that the number of $\\textbf{carries}^1$ of $x+y$ is exactly $k$.\n\nWe adds numbers $\\textbf{by column addition in base-ten}$, just like what we normally do in primary school. For example, there are two carries in the following addition.\n\n![](https://cdn.luogu.com.cn/upload/image_hosting/pfnper3r.png)\n\n$^1$ which means ``进位`` in Chinese."},{"iden":"input","content":"The first line contains an integer $T$ $(1\\leq T\\leq 10^5)$ $-$ the number of test cases.\n\nFor each test case, the first line contains two integers $x, k$ $(1\\leq x < 10^{18}, 0\\leq k \\leq 18)$."},{"iden":"output","content":"For each test case, output one integer representing the answer in one line. If there is no solution, output $-1$ instead."}],"translated_statement":null,"sample_group":[["4\n12345678 0\n12345678 5\n12345678 18\n990099 5","1\n54322\n999999999987654322\n9910"]],"show_order":[],"formal_statement":null,"simple_statement":null,"has_page_source":false}