{"trustable":true,"prependHtml":"\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003e树上有$n$个苹果,编号从$1$到$n$。\u003cbr\u003e计算摘取\u003cb\u003e最多\u003c/b\u003e$m$个苹果的方式数量。\u003cbr\u003e\u003c/div\u003e"}},{"title":"输入","value":{"format":"HTML","content":"输入的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。\u003cbr\u003e每个测试用例包括一行,包含两个整数$n, m$ $(1 \\le m \\le n \\le 10 ^ 5)$。\u003cbr\u003e"}},{"title":"输出","value":{"format":"HTML","content":"对于每个测试用例,输出一个整数,表示取模$10 ^ 9 + 7$后的方式数量。"}},{"title":"示例","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e2\r\n5 2\r\n1000 500\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e16\r\n924129523\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}}]}