{"trustable":false,"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\n Samwell Tarly正在学习绘制魔法矩阵,以保护自己免受白人步行者的伤害。\n \u003cbr\u003e魔法矩阵是一个有n行和m列的矩阵,每个格子都应该涂成黑色或白色。\n \u003cbr\u003eSam想知道有多少种方法来绘制矩阵,满足于最终矩阵至少有A行和B列被绘制为完全黑色。因为答案可能太大,您只需要对998244353取模。\n\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"可能有多个测试用例,不超过5个。你需要一直读到输入结束。\n\u003cbr\u003e对于每个测试用例,输入包含四个整数n、m、A、B。\n\u003cbr\u003e$1 \\leq n,m,A,B \\leq 3000$.\n\u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"对于每个测试用例,输出一行,其中包含答案,对998244353取模。\n\u003cbr\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre\u003e3 4 1 2\n\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre\u003e169\n\u003c/pre\u003e"}}]}