{"trustable":true,"prependHtml":"\u003cstyle type\u003d\"text/css\"\u003e\n h1 { font-size: 1.2em; }\n\u003c/style\u003e\n","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"md\"\u003e\u003cp\u003eMột hoán vị của các số nguyên \u003cspan class\u003d\"math inline\"\u003e$ 1,2,\\ldots,n $\u003c/span\u003e được gọi là \u003cem\u003eđẹp\u003c/em\u003e nếu không có các phần tử kề nhau nào có hiệu số là \u003cspan class\u003d\"math inline\"\u003e$ 1 $\u003c/span\u003e.\u003c/p\u003e\n\u003cp\u003eCho \u003cspan class\u003d\"math inline\"\u003e$ n $\u003c/span\u003e, nhiệm vụ của bạn là đếm số lượng hoán vị đẹp.\u003c/p\u003e\n\u003ch1 id\u003d\"input\"\u003eĐầu vào\u003c/h1\u003e\n\u003cp\u003eDòng đầu vào duy nhất chứa một số nguyên \u003cspan class\u003d\"math inline\"\u003e$ n $\u003c/span\u003e.\u003c/p\u003e\n\u003ch1 id\u003d\"output\"\u003eĐầu ra\u003c/h1\u003e\n\u003cp\u003eIn ra số lượng hoán vị đẹp của \u003cspan class\u003d\"math inline\"\u003e$ 1,2,\\ldots,n $\u003c/span\u003e theo modulo \u003cspan class\u003d\"math inline\"\u003e$ 10^9+7 $\u003c/span\u003e.\u003c/p\u003e\n\u003ch1 id\u003d\"constraints\"\u003eRàng buộc\u003c/h1\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan class\u003d\"math inline\"\u003e$ 1 \\le n \\le 1000 $\u003c/span\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch1 id\u003d\"example\"\u003eVí dụ\u003c/h1\u003e\n\u003ctable class\u003d\"vjudge_sample\"\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\u003e5\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e14\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e"}}]}