{"trustable":false,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e\n .input, .output {\n border: 1px solid #888888;\n }\n .output {\n margin-bottom: 1em;\n position: relative;\n top: -1px;\n }\n .output pre, .input pre {\n background-color: #EFEFEF;\n line-height: 1.25em;\n margin: 0;\n padding: 0.25em;\n }\n \u003c/style\u003e\n \u003clink rel\u003d\"stylesheet\" href\u003d\"//codeforces.org/s/96598/css/problem-statement.css\" type\u003d\"text/css\" /\u003e\n\u003cscript\u003e\n window.katexOptions \u003d {\n delimiters: [\n {left: \u0027$$$$$$\u0027, right: \u0027$$$$$$\u0027, display: true},\n {left: \u0027$$$\u0027, right: \u0027$$$\u0027, display: false},\n {left: \u0027$$\u0027, right: \u0027$$\u0027, display: true},\n {left: \u0027$\u0027, right: \u0027$\u0027, display: false}\n ]\n };\n\u003c/script\u003e\n","sections":[{"title":"题意","value":{"format":"HTML","content":"\u003cfont color\u003dred\u003e一血产生者:罗新新\u003c/font\u003e\u003cbr\u003e\n廖伟这位同学,比较喜欢钻牛角尖,于是找到蒋武说:“上次你给那个大脸猫的问题是不是太简单了,搞的我们被打劫了,要不你也出一个问题考考我”。\u003cbr\u003e\n蒋武说:“你可真行,那我就给你来一道吧。”\u003cbr\u003e\n廖伟说:“好~,谢谢蒋武学长。”\u003cbr\u003e\n蒋武说:“我给你一个棋盘,是一个由2行n列组成的棋盘,你可以给棋盘上的每个单元格涂上了任意黑色或者任意白色,假设两个单元格共用一条边和相同的颜色,那么就认为这个两个单元格是相邻的。如果两个单元格A和B是相邻的,那么A,B属于同一个集和,或者如果A与C相邻,B与C相邻,那么A与B也相邻,那么A,B也是属于同一个集和。问你组成k个集和有多少种方案数,这个数字可能很大,所以答案对998244353取模输出答案。”"}},{"title":"Input","value":{"format":"HTML","content":"唯一的一行包含两个整数n和k(1\u003c\u003dn\u003c\u003d1000,1\u003c\u003dk\u003c\u003d2n) -网格中的列数和所需的集和数。"}},{"title":"Output","value":{"format":"HTML","content":"打印一个整数——组成k个集和有多少种方案数,答案对998244353取模。"}},{"title":"Examples","value":{"format":"HTML","content":"\u003cdiv class\u003d\"sample-test\"\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e3 4\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"output\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Output\n \u003c/div\u003e\n \u003cpre\u003e12\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e4 1\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"output\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Output\n \u003c/div\u003e\n \u003cpre\u003e2\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e1 2\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"output\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Output\n \u003c/div\u003e\n \u003cpre\u003e2\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n\u003c/div\u003e"}},{"title":"Note","value":{"format":"HTML","content":"\u003cp\u003e样例1可能的情况:\u003c/p\u003e\n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/12aef61342a340b71e8687f470af7cb1?v\u003d1627979181\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e"}}]}